American beaver
Castor canadensis
Description The largest of Chicago’s rodents is unmistakable thanks to its buck teeth and flat, scaly tail.
Habitat Along the Des Plaines, Fox, DuPage and other large rivers, but they occasionally find their way closer to the city—they’re active after the rivers thaw in the spring. Isle de la Cache, a small island just east of Romeoville, is a prime beaver-watching spot.
Notes Coveted for their lustrous pelts (nice beaver!), these industrious creatures were nearly trapped out of local existence in the 1700s by Potawatomi Indians and fashion-crazed French traders. But they staged a comeback in the 1960s, likely migrating down the Des Plaines River from Wisconsin.
I LOVE POSSUMS!!!!
The nests you are seeing are not in Rosemont, they are off of 90 in Busse Woods near Arlington Heights, and they are mostly Great Blue Herons along with a few other species.
Bats aren't rodents.
This Place is a Zoo -- Big Brown Bat...Did your writer really think that bats are rodents? They are mammals and are closer related to humans genetically than they are to mice. I could see if there was a ha ha in the little write-up after it says flying rodents, but looks like he/she was serious. I think if Larry Heaney, who is quoted in the article, ever sees this he'll be pretty ashamed and upset to be associated with such a misconception.
I have often noticed a rookery of nests close to Rosemount, IL. Does anyone know if these are eagles or a type of heron?