I swear to god this is true.
I live on a farm, that when we bought it inherited a number of cats, as well as a bunch from a neighbors farm. (owner had died so cats transferred to where the food was). Along with these cats came feline leukemia which is a sickness that will kill a 3 year old cat within a month, but is often picked up when they are kittens. (very sad). They end up being very lethargic and then die. We ended up with over 20 cats, peaking at over 30.
In anycase, there was one cat, we called the mother cat, that seemed to be like the mother hen of the other cats. She would adopt kittens from other cats that didn't seem to have the ability to take care of their own. She was a great mouser and would sit on top of a fence post watching for mice. Or she would do this strange echooy call as she walked through the fields. In anycase it worked for her.
She came down with the feline leukemia and was in a bad state. We did what we could for her, but she was going fast. On the day before she died, she was just lying around when other cats started bringing her presents of mice. She perked up with these gifts but was dead within the day.
The important point here is that other cats
1. knew she was dying, or at least in trouble.
2. brought her gifts which they would not normally do.
3. she accepted these gifts.
All the cats seemed sad after she died, and I supposed that I could be just anthropomorphizing their response. But I don't think so.
I've also heard in other barns, that cats have a hierarchy of places to sit. (on bales of hay). The top cats are the highest.