Hey again! So, I've got another question to ask... I've gone and found another dead rat and during cleaning, I've found that all its incisor teeth are black (the tooth isn't rotting or anything, it just appears black, where it would usually be orange the rest is normal). This struck me as a bit odd, as its commonplace for all rodents to have orange on the incisors. Don't know if this helps, but I live in the UK and I found this particular one in Ely, Cambridgeshire.