Sometimes they look like little eraser heads sticking out of the skin and sometimes they are big lumps of rough calloused-looking skin with no hair. As long as they have the roughness on the outside and they are sticking out of the skin, it is likely a wart. But, as always, if you have doubts about what you're doing, it's best to check with your vet to make sure. Pulling them off with the scalers and them giving them a wart vaccine should fix the problem. I've heard about feeding the warts back to them also, but I've never tried it yet. Luckily it's a problem we haven't had in a few years.