My 6 month old kitten, Casper, has hard black boogers on the rims of his nostrils. His nose is dry to the touch and it seems to hurt him when we try to get it off. I can't imagine what it could be besides the litter or a cold. He uses arm and hammer clumping litter, but my other cats use it too and they don't have it. He is an indoor cat, except when he goes on the balcony a few times a day. Also, we got him about 4 months ago from the animal shelter, they said they found him as a stray. I forgot to add, he acts perfectly healthy other than that. Thanks for any help!