Whoops!
Cutey-patooty.
I had to hand-raise kittens for a couple of reasons, but all came back to them being accidentally separated from the queen. The first batch was a litter of three found in the bottom of a boat, the mother had queened probably the night before, because they still had their little umbilical stumps kind of wet and "new", and the boat owners took the boat early that morning. The kittens weren't discovered until the boat was in the water and it was leaking, so they started searching. Found a litter of kittens and one was already drowned, the other two barely hanging on. My sister (she was with that group) grabbed the remaining kittens and drove over 4 hours to get them to me (I'd just been fired from a job and was big as a house 7mos. pregnant).
The others we don't know how they got separated from the queen, she may have been killed by coyotes or some such. But, they were also just newborns, unopened eyes, fresh umbilical stumps, and so on.
Funny thing about all of them, once they grew older they never gave up this weird little suckling thing they'd do on my hand, in the area between my forefinger and thumb. They'd just latch on and start sucking and fall asleep that way. After a while it got kinda gross, so it had to stop.