Caterpillar nest, I assume

[Brinyan]

Saw this today - is it a nest of caterpillars, or something that attracts them?

[Mirinjawbro]

That looks like a classic caterpillar silk nest, likely created by Spindle Ermine moths or Small Ermine moths.
​In the late spring and early summer (especially May and June), these caterpillars hatch and spin these dense, communal webs to protect themselves from predators while they feast on the foliage.

[smithyithy]

Looks like a deer skull at first glance! Nice spot