Little green oak balls?

Question

so ther are these "balls" that grow on my oak trees. they have a little seed in them, and as they mature, the seed gets attached to the walls of the ball by little hair like fibers. then in mid-end spring, the balls turn brown and drop. What are they?

they are bright green and have little bumps and off white spots.

Answer 1

are you sure they are oak trees b/c the oaks seeds are acorns.  maybe you have a sweetgum tree?  what do the leaves look like?

Answer 2

leechee?

Answer 3

toads that fall off the tree and explode into dust

Answer 4

Common oak gall.

P.S. It is not "leechee". Dennis was probably referring to Lychee, which is pronounced...lie-chee. It's also spelled Litchi or one of any other ways. Also it is the red (not green) fruit of the lychee tree and does not grow on an oak tree.