I spotted this little gadget chugging steadily across a table in the living room:
Nearby, two of its friends / siblings / clones remained near their landing craft:
They’re about 5 mm long and, although there are no larva-size holes visible in the chestnuts tucked inside the burr, that’s definitely where they started their journey.
A few hours later, the rest of the crew bailed out:
The exit hole must be on a nut under the curve of the husk, but they’re sufficiently squishy to wriggle their way out. The little brown dot over on the left belongs to the top larva of a pair queued in the exit corridor:
I lost count at 18. There’s surely more where they came from, so I replaced the plate with a bowl to reduce the quantum tunneling probability.
In an ideal world, they’d grow up to be chestnut weevils, but I put them out near the suet feeder and, a few hours later, my offering was accepted.
The appendages at the tip of her abdomen were spread to the sides and her whole body moved in small circles, although I couldn’t get a good view of the proceedings. Building an ootheca apparently requires concerted effort, as she was still hard at work when dusk fell.