scary foam

scary foam
Originally uploaded by wereldmuis.

While tramping around Lincoln woods, I noticed that a number of trees had a little pile of foam down at the bottom of their trunks. The lump of foam in this photo was about the size of my fist. I noticed some foam seemed to be running down the tree bark, in a thin layer, as well. It literally looks like soap foam. You might speculate that someone went through the woods tossing soap on the trees, after all, people do the craziest things... However, here are my top ideas for what produced the foam:

1) It's something produced by the tree itself, possibly in defense against an insect.
2) It's produced by a tree frog.
3) It's produced by some insect.
4) It's produced by alien invaders, and we'll all soon be assimilated. Or get our brains eaten.

In any case, this requires further investigation! BTW, I did not poke, prod, or otherwise disturb the foam. I know that if I did so, the alien would leap out of the foam and eat through my abdomen in a heartbeat.

[Close, but no cigar. Turns out the most likely candidate is slime flux, also known as wetwood.]