You may have to look very closely at these photos to make them out. Above the zendo door is a mud bowl swallow nest. Yesterday when I touched my fingers inside the nest I could feel warm bodies. There was no squeaking though.

The camera angle is tricky, with no room to manoeuvre. Baby swallows. 🐦

Swallow chick with white fluff behind and wide white mouth visible behind a small dark beak. One eye can be seen.
Swallow chick with wide white mouth visible behind a small dark beak. One eye can be seen. At least one other chick can be discerned, maybe even 3.