bed bugs

Pest Poop 101

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by The Bug Doctor

It may sound funny but your average bug man who’s been around for any length of time has probably taken a course on poop. Let’s face it, sometimes it may be the only evidence left behind (no pun intended) from which to identify your pest problem and thereby go about the business of solving it. I’ve had hundreds of clients over the years who purchased mouse bait, glue boards, traps and the like because they found small black fecal droppings on there counter tops. After about a week with no rodent but plenty more droppings they called me in and within minutes I let them know they need a roach job, not a mouse call.

For this article we’ll just handle just the most common id problems but if you need to verify something not listed please use the Ask the Bug Doctor page where you can also upload a picture and I’ll be happy to help.

Mouse verses roach

Mouse droppings are confused for roach droppings and vice versa quite a bit. Of course not all roaches produce big enough fecal matter to be compared and if it is hanging or smeared on a vertical wall you can pretty much rule out mice. Roaches such as the American, Australian or Oriental usually are the prime suspects if you have large roach droppings. Mice produce a lot of droppings, some say as many as 150 perPicture 43 225x300 Pest Poop 101 day while roaches do not so that is one of our first clues. However, roaches do tend to live in quasi nests and the pellets can add up giving you the illusion of having a mouse so don’t let this be your only rule. Mice poop just about where ever they run, on top of the refrigerator, in your strainer or drawers you name it. If they hang out in a place for a length of time or frequent a spot often the droppings may build up. Roaches tend to deposit their fecal matter near or in there nesting site. For a roach the odor is like a homing beacon so they can return to their favorable spot each evening when the nightly raid is done. Again this is a general tendency so keep that in mind. If you want to be 100% sure the best way is to take a close look at what your invader has left behind. Mouse droppings will almost always be somewhat tear dropped shaped. Round at one end and pointed at the other while a roaches dropping will be for the most part chunk like and almost square-ish. If you have a magnifying glass you may also see ridges in the roach dropping and you will never see that from a mouse. Any colored fecal matter such as green or red will most certainly be from a mouse and indicates they have eaten your green colored D-con where as a roaches poo is never anything but black regardless. Ok, if you’re still with me and not grossed out enough yet let’s look at the other most common misidentified pest poop.

Frog verses rat verses snake verses lizard

Picture 73 Pest Poop 101Rat fecal matter is very similar to mice. The exceptions are of course the size and the amount produced. Just as there are different kinds of mice there are also different rats. The 2 most common are the Norway and the Roof rat with the Norway excrement being the larger of the two. Rat droppings will often have a hair or two in them as well but look for all intensive purposes like a mouse’s only bigger. Frog poo is often mistaken for rats. It varies a bit as for some species as the texture is much softer and may take different shapes when it comes out or dries. Frog doo is usually much larger however and very delicate when set. If you poke the dropping it will usually flake or crumble apart quite easily. Also if you look closely you may see insect parts in the matter and sometimes small plant debris that may look something like a hair. I’m not exactly sure how often a frog goes and while it’s seldom inside a structure a lot of people will be fooled in to thinking they have a hoard of rats living just outside the door when it is really Picture 83 300x162 Pest Poop 101just some frogs living in their soffits. Now for the last dung example and none to soon, I’m running out of poop words. Snake & lizard doo doo is very often confused for both rat and frog but there is one quick way you can always tell the difference. These two critters dropping almost always have a white tip. The reason for the color is that they both incorporate urine with the bowel movement and that produces the white colored end. Now that’s about as far as my knowledge goes on the snake and lizard poop but if you’re in Iowa reading this I think you can rule out lizard if you see this. That is unless Hiawatha was somehow infested with them and they learned to survive the winters since I was a little boy.

Well, no certificate comes with the study but hopefully you’ve learned a little bit about the #2 world of a few common pests. I didn’t think I could write so much on this subject but apparently I paid attention to my poop class after all. I may just have to take back what I thought about the instructor as I sat through 2 hours of fecal matter training. “Man this guy is FULL of it.”

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  • Mike Griffin

    The last picture in the article, what animal is it from?  I have the exact looking ones in my garage.  I want it out!!

  • The Bug Doctor

    This I believe was lizard poo–we have a lot of those critters around here but snake too too is quite similar.

  • Sarra

    I found one similar last month in the study, got an en suite to it and there is a gap around the toilet’s pipe to outside that I’ve ivy branch coming in. Today I’ve found another one in the lounge, it was stuck to the carpet which suggest it was moist, it is a bit slimmer than the photo but same length.  Any advice to what it could be, I took a photo if that helps.

  • Sarra

    Forgot to add to my last comment, it does not have the white bit but have a lighter streak along it.

  • The Bug Doctor

    Yea, send the pic to my ask the bug doctor and I’ll look.

  • Sarra

    Thank you for your reply,
    Yesterday after a close inspection found another one stuck to the skirting in lounge. After uploading the photos they become more clear, they look to me now like a dead slug! I am attaching several photos of both… thank you again for your help. Uploaded the picture by reply to your email.
    ps the one on the tissue looks quite peculiar when enlarged, seems like it had an ear, scary!

  • Scared

    I found poo like in the picture in my kitchen and in one of my bedrooms omg I’m sending a picture is it snake poo?

  • The Bug Doctor

    Please send it along–just use my upload feature here
    Hopefully I can help

  • Katy

    Very helpful article. I feared that I had a rat in the garage. I am happy to see it is a lizard. Thank you.

  • The Bug Doctor

    Thank You Katy,
    I’m glad it helped!

  • Michi

    I live in the tropics so lizards are a way of life. However the last two mornings I have woken to see a lizard turd near to my pillow. Any explanation for this behaviour???

  • Cricket

    I have mice/rats in my yard, I also have my dogs. I want to get rid of the rodents without hurting my pets. Is there any kind of ‘poop’ (such as snake poop) that I can place around the mouse holes so they’ll leave?

  • The Bug Doctor

    I think you’d have better luck with Fox urine but I’m not a 100% sure on those types of methods. You could use snap traps (T-Rex) in tamper resistant stations that dogs cannot get into. The T-rex you can get at Lowes–they are black plastic and there low profile allows them to be just as effective as a traditional wooden snap trap–The stations you’d have to get on line or at a pest control DIY store. Check this link to see these. and

    Good luck

  • The Bug Doctor

    Not sure…. Do you have a window at the head of the bed he may want to get out of? That is a bit strange & I can’t imagine it has anything nefarious in mind.

  • Frustrated

    I have a very smart mouse. I left out two different types of peanut butter laden traps two nights in a row. Both nights the mouse ate the peanut butter, but never tripped the traps. One trap is reusable, the other trap is the old-time wooden trap.

    Any advice?


  • The Bug Doctor

    Try putting a washer or button on the end of a string with some peanut butter on it and hang it up directly over the trap tongue. Approx. 3 to 4 inches high. Or check out my articles in the rat and mice topic area

  • Disgusted

    I have the pellets in my utility room and I thought it was a mouse, I’ve set all kinds of trap andthe poo is on the traps and nothing eaten or tripped. I put down sticky traps and the poo is on the traps and nothing else. I’ve cleaned and bug srpayed. Your thoughts?

  • Disgusted

    Looks like I’ve answered part of my question, it’s as mall bug that looks like dropping when it dies. Guess the bug spray worked.

  • The Bug Doctor

    Ahh–some small beetles can look like droppings…. if you have any pet food and/or other food type products in the room, check em out to rule out stored product pests.

  • Ron Rammelkamp

    Hi there, based on what I’ve read from this site, I could have roaches, or mice…the poop sort of looks like both in a couple of spots. BUT….we had a mysterious thing happen in our kitchen. Pre-shelled walnuts appeared in a pile in a drawer next to the sink. My wife and I have no idea how they got there from the bowl on top of the counter…? We removed the nuts and joked that one of us was sleep walking. A few days later…BACK IN THE DRAWER! We couldn’t believe it! A day or two later we see these droppings in a cabinet under that drawer and under the sink and one drawer over. All of these connect somewhat with a hole and tube for water to get to the dishwasher. We also saw a few dropping by the small bowl on top of the counter and a few by a bowl that had (but no longer) a few small potatoes in it. Did we have a mouse or rat move the walnuts? We assume this is happening at night when we are asleep, where do they go during the day? Next course of action?

  • The Bug Doctor

    I’d say you have a rodent for sure. Mouse or rat? Not so sure… I’ve had mice do the “walnut gathering” thing with a variety of foods but more over they just kind of eat and scamper, eat and move leaving crumbs maybe from their nibbling behind. Rats are horders and will take foods back to their nest to store for future use… So that behavior is a little odd but at least it rules out roaches…During the day yhe rodent most likely heads up under the false bottom of a cabinet,behind in in the fridge motor or dishwasher or back into the voids of the wall through an unsealed pipe hole…. Any house can have dozens of suitable locations in just the kitchen alone.. (long forgotten and mostly unused drawers are always suspect) I’d simply lay out some glue boards and you most likely will get your critter in the first night or two. You can check out my video on How to set traps for some help.

    Good luck

  • Andrew

    I have been finding mouse dropping on the kitchen counter and behind microwave also have seen one run across sink area last night I have put out many wooden snap traps with peanut butter on them but for two days now no luck any thing else I should do

  • The Bug Doctor

    Check out this video and it may help

    Trap placement is key

  • Kayla

    Hi. I live in an apartment and in the last couple months have been noticing some droppings here and there on the floor along the walls for the most part. I have tried to find an answer for what it is but still not sure. Its bigger than mouse droppings in length and has a smooth appearance, pointed on the ends and medium brown in color. Theres usually just one dropping in the area. Ive never seen the culprit and other than the droppings i havent seen any other signs of it. Does anyone know what it may be? Theres an attached picture.

  • The Bug Doctor

    Hey there Kayla,
    I think you’ve got a slug there and not a dropping.

  • Dave

    I have found this round black sticky dropping, each time there’s just one in different rooms of the house. When it falls on clothing or on the rug it stains it. at first i tot it was some kind of egg sac but now i believe it is droppings because of its frequency. Any idea what that could be?

  • Amal Ibrahim

    Thank you so much for this as I just moved and was worried that rats were also residing in our house. But since I’m in the desert, it’s quite possible they’re geckos. Maybe? I’ve also seen a wormlike bug that gets stuck on the wall and also looks similar to the last picture. Do lizards leave droppings on walls?

  • The Bug Doctor

    Yes, lizard, gecko, anoles all climb very well and with that they sometimes have to “go” while on a vertical surface– sometimes it does stick.

  • The Bug Doctor

    No sorry. Can you send a pic? You can use my ask the Bug Doctor tab…

  • Wakefield

    Rat or roach? Really grossed out either way.

  • The Bug Doctor

    I hear ya, nice to know the difference though

  • Traci

    I think we have some American or Oriental roaches. We’ve had mice in previous homes and can tell that the poops we’ve been finding aren’t mouse, plus we see a big roach every once in a while. My question is, since we see a roach (live ones and dead ones) every once in a while, does that mean we have a big infestation (like with the smaller roaches, you see them when the population is too big for the food source) or that we only have a few. From what I can gather from other articles, the big ones don’t typically live in homes, so I’m hoping we only have a small amount!! What do you think?

  • The Bug Doctor

    I’m sorry if I led you to believe that they “can’t” (big roaches) live in homes because they can and do– if the moisture and conditions are right they have little problem thriving inside… As far as extent of your problem based on what you’ve said. It doesn’t sound like a huge problem but these things often go undetected ‘in the walls’ and build up in there. Best to have a pro come out and eyeball the situation for that answer.

  • Traci

    Ok, thanks for your reply!

  • Rebekah

    We found poop pouring out of the walls when we ripped off the trim of our newly purchased house during major remodeling. Can you tell me what kind it is and how to clean it up? So far we know there was a major rat infestation in the attic, I’m hoping beyond hope that there were mice in the attic as well and it dropped down into the space between the walls. We have cleared out the insulation and are in the process of cleaning up the rest of the poop in the attic, but I’m not sure how to get rid of it because it’s in between the walls. When we sweep/vacuum it up, the next day more has fallen out. Any advice would be helpful!!! Sorry the picture is sideways!

  • Amber Stewart

    I’m hoping you can help me out – I live in the South, in an old condo building, and every once in a while I see a small black, almost rubbery dropping. Sometimes they’re even on my bed/pillow. I pick them up with a tissue (they’re usually very small), spray the area with a tea tree oil spray, and flush the tissue.

    If you say this is a roach I’ll never feel safe again, but I would appreciate the advice.

  • The Bug Doctor

    Small & black could mean a lot of different bugs…but rubbery can throws me. I think I’d need to see a pic to truly be able to help you out without guessing…

  • Concerned Cat Owner

    Thank you for this. We did hope it was lizard poo as the cat had brought one in this morning. But this post has certainly relieved our fears. Thank you.

  • The Bug Doctor

    Glad it helped

  • Cutiepiee

    Thanks! I finally figured it out! Lizard poo

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