Ok, I just got the crap scared out of me. I am 55 years old and have lived in SW Iowa all my life. I have lived here 36 years and my grandparents lived here 50 years. As far as snakes go I only see a few Garter Snakes, an occasional Bull Snake, and one Blue Racer when I was about 10, until today that is. I think I just saw a Rattlesnake. It was only a quick look as it slithered into the tall grass but it had a diamond pattern on it. It was not a large snake, 2-3 feet I'd say and about as big around as a 1" pipe. It was vibrating it's tail very rapidly but it sounded more like a bumble bee than a rattle. So my question is was this a rattler or is there another snake that mimics the rattler by vibrating it's tail? The last report of a rattler I heard of in this area was back in the 1960's. I may never walk through the tall grass again, yikes!

Oh my gosh hissing at you well at least you didn't step on it so the hissing was probably a good thing. That alone would have made me cringe lol.

It's an Eastern Milk Snake. They are harmless and non-venomous.

You correctly ID'd the one at the top of the photo as an Eastern Garter(Thamnophis sirtalis sirtalis). The dark one at the bottom of the photo is a young Black Rat Snake(Pantherophis obsoletta). Black Rats don't hatch out black; they enter the world as a silvery-gray snake with a bold pattern of black blotches and lines, and gradually turn darker with each skin shed. This snake is still fairly young, as you can still see its blotched pattern visible, like the spots on a black leopard. Where you live, adult Black Rats usually are jet black with white undersides and throats, although in many places throughout their range, they will keep at least some visible dorsal pattern throughout their lives. I'm guessing that with different species coming into the basement, species with very different feeding habits, they are preparing to hibernate there. Both of these snakes are harmless, and will leave come spring. The presence of the Black Rats could be a deterrent for rodents to enter your home during winter.