Hi, I am just curious, I know male guinea pigs have sweat glands on their behind, but what should it exactly look like? I have a light coloured piggie, and the sweat gland is kind of waxy and brown, but it looks like it's coming off? Should I be cleaning this off or is it suppose to be there? sorry if I sound stupid. He is due for a bath soon mind, but I was just curious really to see if this is normal? thanks.