I have a batch of five week old chicks that have been living in the house their whole lives so far. Just this week I noticed a bump like this on two of them and the only thing I can think of it could be is dry pox. The bump is very hard. Since it is spread by mosquitoes, it seems really unlikely but that could be it, although I suppose it’s possible. Mosquitos do occasionally get in the house….I’ve never had it in any of my other chickens, though, so I’m wondering if there’s anything else it could be?