You don't hear about rabies that often. We're generally good about getting our pets vaccinated, and rabies bites by wild animals are relatively rare.

But they do occur, and right now, cases of rabies are on the rise in parts of the United States. For example, the number of rabies diagnoses in bats has doubled in Illinois since this time last year, reports the Chicago Tribune.

Because of this uptick in rabies cases and because you're more likely to run into animals carrying the virus during the warmer months, here's a look at some wild animals to watch out for and some of the animals we often incorrectly assume pose a rabies threat.

Animals more likely to carry rabies

brown bat Rabid bats can often be found on the ground because their symptoms keep them from flying. (Photo: Alex Gorzen/flickr)

Not all wild animals are prone to the virus. The wild animals that are most likely to carry rabies in the U.S. are bats, raccoons, coyotes, foxes and skunks, according to the Humane Society. They are all nocturnal animals, so seeing any of these creatures out during the day may be a hint that they're infected. However, it’s not always a definite indicator; sometimes these animals are working extra hard to provide food for their families, but it's something to take note of.

There are two categories of displayed behaviors in rabid animals. The first type is “dumb” rabies and the second is “furious rabies.” The most common symptoms depend on the form of the disease the animal has.

Animals that have furious rabies may be very agitated or extremely aggressive towards other animals, objects or even their own limbs (resulting in self-mutilation). These animals typically drool excessively, which can explain the foaming at the mouth associated with rabies.

Animals with dumb rabies may often seem tame and don't appear to be bothered by people. They can look lethargic and often have signs of paralysis. Because of the paralysis, the animal can drool (again the common "foaming at the mouth") and have odd facial expressions.

Bats are most likely to show symptoms of dumb rabies, according to a training manual created by the New York State Department of Environmental Conservation and Cornell University. Rabid bats are often found on the ground because they can't fly due to their symptoms. However, any rabid animal can show signs of either type of rabies. Watch out for behaviors such as erratic wandering, confusion and unusual aggressiveness if you spot any of these animals during the day.

Different wild animals are more likely to carry the disease in different parts of the country. Raccoons living in the eastern states are most likely to contract rabies than they are in other states. Skunks with rabies have also been reported in the eastern states, but skunk rabies is mostly seen in the central U.S. Cases of rabies in foxes are most prevalent in Arizona, Texas and the eastern states. Coyotes with rabies are typically found in southern Texas. There's no specific area where bats are more likely to have rabies.

Animals unlikely to carry rabies

angry opossum in a flower pot Sometimes opossums will foam at the mouth and act aggressively, using fake rabies systems as a scare tactic. (Photo: Becky Sheridan/Shutterstock)

People often assume that opossums and rodents can carry the rabies virus, but it's rare for any of these creatures to host the virus. According to the Humane Society, opossums can look like they have rabies symptoms but they do it as a scare tactic. To defend themselves, opossums will often foam at the mouth, sway and act unusually aggressive. Opossums also have a lower body temperature than most mammals, which might be a reason they rarely contract rabies.

Rodents such as rats, squirrels and rabbits almost never carry rabies, reports the Centers for Disease Control and Prevention. This might be because these creatures are too small to survive an attack by a larger animal that is infected. The Humane Society says that squirrels can fall victim to roundworm brain parasites, which causes symptoms that strongly resemble those of rabies.