Slime Creatures From Outer Space

I went out to the trash dumpster yesterday.  Our lids have to be unchained as we have bear problems.  I opened the lid and tossed my bag inside.  And something was moving in there.  It was so dark I couldn't tell what it was.  I went back inside and returned with my flashlight.  Something dark and round looking scurried underneath a bag of trash.  After a few minutes of jostling things around, I discovered what the mystery creature was.

"911 what is your emergency..." 
"There's a rattlesnake in the trash dumpster at my condo complex."
"A what?"
"A rattlesnake.  This thing has 6 foot walls.  I have no idea how it got in there, but I don't think it can get out and it might bite some unsuspecting person."
"It's not something we can help you with."  They hung up.  Then a few minutes go by and someone from the Wildlife and Parks calls me.  I explained the snake had no way out and someone might get bit.
"How did it get in there?"
"How the hell should I know."
"We'll send someone out."
Some guy from animal control comes out.  He can't find the snake.  I think he thought I was a kook or maybe saw some tubing.  Then it struck his pole and started rattling.
"Rattle Snake," I said.
Then some other guy from Parks & Wildlife comes buy and a deputy sheriff. Well, they finally got it out of there. And put it in a bucket and said they'd let it go out in the woods.