hii, ive noticed that my guinea pigs have some grey dots in their fur. the dots arent moving and seem quite clingy but i can get them out if i try with my fingers. loulou’s (beige and white fluffy one) fur also looks bitten but I'm not sure of it could be by her or her sisters. however, ive heard them argue a bit and her sisters have also been sprayed by pee. its strange because i cant find any sort of lice-like insects that it could be. i also treated all of my guinea pigs and their cage last month for lice because they had a few. please let me know if you have any idea of what this could be and how i could help her, thank you xx