Well because he is a kitten (if he is under 3 week old or so he would do that) but if he is older i don't have a clue sorry

 I had a puppy a maltese that did the same thing. It had anaemia and died very soon after. Please take your kitten to a vet.

 I had a puppy that was doing the same thing. He had been taken from his mom too early. He was in shock one morning his blood sugar had dropped. We took him to the vet but he had anemia so bad, it was too late and he died a few hours later. Please take your kitten to the vet because if it is losing blood, it is a very serious thing.

 Ok,you should really see a vet now.