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 per
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
Rat 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 
just 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.”
