An unknown object was in the bee box?

A male beekeeper has been practicing beekeeping for some time and today he found this object lying open in his colony. He noticed that the beehive was completely properly and well closed and that it was lying directly inside as if someone with a lot of experience had placed it properly and neatly. So the question is why was it lying there and what is it? (The only other person who saw this object was another beekeeper who has a personal problem with my friend. If this information could help.)