The bee moths, Aphomia, are in the Pyralidae Family. I know nothing about these moths, but when I opened a bird box to check it today, I saw this mass of tubular shaped cocoons and little yellow larvae, one per tube. The door to the bird house was firmly stuck shut and it took some time to pry open. I had no idea what could be making it so difficult to open and was surprised to see this nest with very strong sticky fibres which had, it turns out, cemented the door shut. The door itself was grooved with long channels, corresponding to the cocoons.

I had to go to Bug Guide for an answer. There I learned what made this nest and that there are only 3 species in North America, and this one is most likely Aphomia sociella. Apparently they get their name because their larvae often develop in bee's nests. However, Bug Guide also notes that they can develop in rodent nests, and that is interesting because prior to the moths taking over, this nest box had housed a family of mice!