Instructions
Watch your rat's behavior. Rats with fleas tend to scratch more vigorously than usual.
Inspect the rat's skin by holding it and parting the fur. A rat with fleas tends to have skin that is reddened and inflamed from constant scratching.
Look for small jumping insects on your rat. Fleas are very small, but they are visible to the naked eye.
Look for small black dots in your rat's fur. These black dots are the fleas' feces and they are mostly composed of blood. To figure out if something is debris or flea fecal matter, drop a small amount of water on it. If the specks turn red, then fleas have been feeding on your rat.
How to Tell If a Rat Has Fleas
Rats are excellent, low-maintenance pets, but like any other mammal, may develop a case of external parasites. While there is a flea that is specific to rats, domestic rats may also contract this parasite from contact with cats and dogs that carry fleas. Flea combs and medication Ivermectin are both methods that are commonly used to treat fleas, but before you can treat this condition, you need to diagnose it.