Pest Poop 101

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 permouse poop vs. roach poop 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

Norway vs roof rat pestcemetery.comRat 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 lizard or snake dropping pestcemetery.comjust 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.”

About The Bug Doctor

Jerry Schappert is a certified pest control operator and Associate Certified Entomologist with over two and a half decades of experience from birds to termites and everything in between. He started as a route technician and worked his way up to commercial/national accounts representative. Always learning in his craft he is familiar with rural pest services and big city control techniques. Jerry has owned and operated a successful pest control company since 1993 in Ocala,Florida. While his knowledge and practical application has benefitted his community Jerry wanted to impart his wisdom on a broader scale to help many more. was born from that idea in 2007 and has been well received. It is the goal of this site to inform you with his keen insights and safely guide you through your pest control treatment needs.
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  • SuperSmurfette

    Can someone tell me what poop this is? I’m suspecting mouse, but then there is a separate white next to the black? Found this in my kitchen. I find one or two every morning in my kitchen now.

  • SuperSmurfette

    Hmm don’t think the pic loaded I’ll try again.

  • bn15

    Just moved to the desert in Twentynine Palms, CA. found this in my kitchen cabinet…..

  • bn15

    Don’t think photo loaded.


    Hello, a recent widow, I decided to keep myself busy with home remodelling. I chose a lovely sage green couch we bought as inspiration. When I took seat cushions off to clean it, i found 3 rat-sized holes. With my little flashlite, it was pretty easy to tell by the hundreds of 1/4 in. pretty cylindrical droppings, that I had the bloomin’ roof rats again! BUT…the contractor was workin under the sink one day and the next day he was gonna close access to pipes and there it was…bigger tham mouse/rat droppings, whatever it was had gotten the cheese and set off the small mouse trap, got away… and stopped to do his business in 5 corners of my 1 bdr. home..It looked almost exactly like the 1 1/2 in. dropping just like the pic next to the green measuring tape on your website! But, I did not notice any white. No teeth, hair, or little hands….Everywhere I found one, it seemed to still be fresh and pointed on one or both ends. When they dried, it took on a more chalky look. Whatever it is, it stays along the baseboards and is extremely quiet..I never hear any rustling from the rats or the…potential heart-attack if he’s accidently seen..I live in coastal Texas, between Houston and Galveston. Short of marrying me, is there anyway u can help me? I called exteriminators, who said it was a dog..c’mon and they put out a few sticky boards for rats who venture outa my couch and I haven’t had much luck with sticky boards..i just seem to catch big chunks of hair..well, any info is better than the perplexed state I am now in. Thanks, Teri

  • Wow Teri, that’s crazy. For rats I sometimes ‘pre-bait’ the trap with it unset. Do this until they are comfortable and then set. I think I might pay someone to come get that couch too…that’s just me. There are plenty of good/great exterminators I know in Texas if you need help. Write to me using the ask the bug doctor tab at the top of my blog and I’ll give you their info if you like.

  • Lynn

    Thank you for the information you have provided! I have been scared that we have a rodent problem. I live in Arizona and we have lots of lizards in our back yard. They often end up drowned in our pool skimmer. It has been very hot and lately they have been hanging out under our covered patio. It looked like mouse or rat poo but I’ve never seen a mouse or caught one. However I have seen lizards on the patio behind the cooler. I called our pest inspector who told me he thought it looked like mouse poo and put down sticky traps. We caught nothing and more poo. Still I felt it was the lizards. One character all poo had was a white tip at the end. I am confident it is lizard poo as I thought! Reading your opinion on the matter has me 100% sure. Thank you for the info, in can rest assured no mice or rats just our friendly lizards we don’t mind because they eat backyard bugs!!!!! I can finally go swim at night without the feeling that something may scurry by!

  • Ha!! I’m glad you can enjoy your late night swims… 😉

    Thanks for your kind words

  • Karla

    We’ve had a couple of roaches around the kitchen in the floor these past couple of months. I found this droppings on top of my counter and some of my sealed bread eaten, as if it was nibbled on. Can you pls tell me what type of droppings these are. I’m not sure if it’s the roaches or we have mice.

  • Di Spencer

    Thank u for ur info. I thought I had roaches but apparently I have a blizzard or snake. Now I have to figure out how to get rid of it.

  • Debra Martin

    Help! We have a home in central Florida. When we come back in winter there are brown trailing marks on my white cabinets, refrigerator and oddly on some appliance cords, plastic trays and such. These marks are flat and come off with Clorox cleanup. We never see any pests while here and these marks do not appear again until we return the next year. What is it, please!

  • Sounds like Australian or American roaches are partying a bit while you’re gone. I see this type of thing quite a bit…. Call your local pro out and you should be just fine.

  • You’re welcome

  • Wendy

    I need some help. I have found what I thought was mouse poop on the side of the house. Right by where the AC condensation pipe comes out. I don’t have a picture but its black, some are squarish like roach poop and some are longer like a grain or rice and some are tear shapped. but mostly small and black. I thought for sure it was mice. but here is the problem:
    – This has been going on for several years, once a year, in the same exact spot and around the same time of the year!
    I though it was mice because I thought they were looking for water but last year I removed the source of water from there, but the poop still appears in that same spot. and its not because of past smell, since once I solve the problem I thoroughly wash the area with soap and clorox more than once. at one point I thought it may be because I have a tree that produces small round like fruit and it falls early in the year, but the trees are not near there and there is nothing no where else in the yard but that same 2′ by 2′ corner, and no signs of fruit there or any seeds eaten.
    l suffer from severe OCD so I obsess about these sort of things and I know exactly what goes on in my yard, because I inspect almost once a week if not more since I have small children.
    last year the poop appeared on February 18 and this year Feb. 13. this also happened around the same time on previous years. The fact that there is no poop on any other area of the yard or the “travel path” to that corner leads me to believe its not mice. can any other animal nest or appear based on time of the year? This seems too weird!
    also, in previous years I have placed traps, poison, tons of cayene pepper on floor and nothing! I never catch any thing or see anything, but it usually takes me about a month to get rid of whatever is leaving the droppings. what is even more weird is that i clean the poop, put cayene pepper on the floor and the powder on the floor doesn’t seem disturbed, no drag or tail marks at all if it was mice walking by to leave droppings again, but the droppings appear the next morning!
    I have looked up to see if it could be signs of bats or birds in the corner of the roofing but see nothing. any idea of what this could be? it seems too weird for mice to come to a same exact spot almost exactly around the same time of the year each year!

    Help is greatly appreciated

  • Dyllon Rhea

    If you have Geckos or other small lizards in your area it’s possible that’s from them. I get the brown markings on the siding and undersiding of my house where Geckos like to hang out and use the restroom.

  • Kristy Clougherty

    I have a creature, but no poop to help me identify. Whatever it is it manages to take peanut butter out of the traps without setting them off. It’s been gathering nesting materials tearing up a stress ball and eating through my daughters backpack for a paper towel. It does not care to go for other food scraps in the pack or other areas of the house with access. This has been going on for two weeks with no scat. I was thinking mouse, but wondering if lizards drop less waste. Our house is sealed off and I can’t seem to find where it’s coming/going. Please help. Pasadena, CA