Tent-making caterpillars

Writhing mass of adult tent caterpillars in their silk pod

Here’s a photo NOT for the easily-grossed-out, and you know who you are. It’s the destructive larvae of certain moths, all rolled into a fist-sized bundle of squishy goodness, surrounded by their night shelter of very strong silk. It took me and a stick about three minutes to break one tent open for inspection, so that is powerful stuff they spin.

Silken pods were glued to many branches of every cottonwood. Tent-making caterpillars defoliate portions of the tree but do not kill it. Birds that feast on these caterpillars are less frequently found here now, due to habitat fragmentation.  (Insert frowny face here.)

Up an idyllic side canyon off of Horseshoe. Maybe there is rock art there, too...

According to Wikipedia, tent caterpillars can detect vibrations at the frequency of wing beats of one of their natural enemies. Wow. My question is: what do they then DO about it?!?

And, finally, your most fascinating caterpillar fact for the day: they have 4ooo muscles! (Humans have 629.)