help me

Hey everyone, ive been breeding rats for a while now, and while examining my litter, j found a cyst of some sort on my two week old dumbo male. Does anyone know what this is and why it appeared so suddenly? Please help, i dont want this to cause him to pass at such a young age.

I have a rescue rat who was neglected quite badly in her previous home. She’s been with me for nearly 3 weeks now and I’ve been trying desperately to get her to be tame. She was never taken out of her cage in her previous home and from what we know she bit the owner when they first got her as a...