Duffy was a "singleton" foster kitten, which means he was the only one in the litter.  They are a bit more of a challenge to foster because they don't have siblings to cuddle or play with.  They learn a lot from each other, including to not bite because they get the same treatment back.
So when I foster just one bottle baby, I get a lot more bites and scratches.  Of course I do because I am mom, playmate, and everything rolled into one.  I still love to foster these little singletons because they bond pretty tightly to me and it is like having a BFF with you all the time!  It also helps that they are so small, they really can't do too much damage.
Here is Duffy cute as can be at about 3 weeks old.  He walks a little wobbly and and is pretty funny.  The biting and scratching comes when he gets a few weeks older, so I enjoy it while it lasts!

Flashback a few years ago to this wild and crazy batch of foster kittens.  Can you believe these 3 are siblings???
They loved their little hammock and would all pile in it together. Fostering kittens can often be quite entertaining. Like all tiny kittens, they got wild and crazy, and in this photo they look like they are clown kittens!