Dead Black and Yellow Mud Daubers found in house?

Question

A couple days ago I found a mud dauber dying on my floor, just twitching, almost near death. This morning in my windowsill I found two more mud daubers, already long-dead, side by side.

What could be killing these, and why are they inside my home?

Answer 1

They are dying of starvation, not being outside to feed on flower nectar.

They're getting inside your house probably because they have mud nests nearby, like under the porch awnings, or under the windows outside the house, yet near enough to an opening to accidentally get inside every now and then.

Note: These wasps hunt and paralyze spiders which they put inside their mud nests for their larvae to feed on.

These insects are wonderful, beautiful creatures that do our planet a great deal of good, while they bring beauty and wonder into our lives.

Answer 2

It could be residue from insecticide sprayed on their nest.  They may have been trying to establish a new nest.