Can somebody tell me what this is?
 

I have about forty Oak Trees and Three Crab Apple Trees on my Property in Plymouth. Tiny apples and acorns cover the lawn every summer/fall. This year I have these things all over and I cant figure out what they are or what tree they come from. My neighbor has the same thing and he's baffled too. My first guess was a mutated apple so I took a little taste. Immediate numbness and tingling on my lips and tounge (good thing I didn't swallow it). Any guesses?

I call them puffer balls. I wouldnt eat that dood. comes off some kinda tree, I get them in my yard too. When they dry out they get real brittle and if you step on them they crunch and puff this wierd smokey stuff out. I don't know what they are for real though. Probably some kind of seed or dried skunk gonad

Boil that Dust Speck! Boil that Dust Speck!

Listen for any Yips or Yaps before you step on it.

definitely alien infestation

I get them too. No idea where they come from as I only have Oak and maple trees around me. They are some kinda fruit as when I stepped on one it looked like it was kinda juicy.

I live on 15 acres of oak tree. They come from the oaks but I don't know exactly how.

I've seen them around as well. I was never tempted to try and eat one though! No ide what they are, but I too would like to know.

oak gall. insects put their eggs in the twigs to incubate and it forms that ball. I can't remember what insect.

ok back now google says it's a wasp.

I wonder why I've never seen them before. Maybe its a cyclical thing. Thanks for the answer.

oak apples maybe http://www.jmu.edu/biology/k12/galls/oakapp.htm

That be it.

oops, looks like Fred beat me to it.

Kind of funny you asked, because I picked up a couple yesterday and for the first time gave considerable thought as to what they were. Now I know.