We are a half-way house for single mom cats and their unplanned kittens. My wife talked me into doing this years ago with the Humane Society and we have had almost 50 cats come through our house. Some needing meds, socialization, or growing until they weigh at least 2 lbs (Those were some very small kittens.). It was great, but we took a break for the last year and a half as we put the house on the market. Now we have the house off for a month, so we decided to have a group come through. We have three new kittens with ear mites, all needing to put on a few pounds before they can be adopted. It's great fun.
Our cats, that always live with us, have had to do a little adjusting. Emma's trying to make friends, but all her growling is a little intimidating. She's starting to share her toys under the door, though. That might just be a trick to get one close enough to grab and eat.
The kittens are actually very cute, and not quite a demonic as this one looks.