I have a grumpy old father-in-law who needs 24/7 care in a assisted living environment, but the catch is he is rude and cantankerous to others around and does not care. What do I do?

What was his behavior like before going into assisted living? Was he always somewhat grumpy and cantankerous? If this is something newe, there could be lots of reasons. Some of it may be anger at losing independence and having to rely on someone else for basic needs. He could see this as the beginning of the end and reacting to that. If you have had a close relationship with him, can you ignore his grumpiness to give him special attention from time to time? I wish you well.

connie: does he have alzheimer's? If so, that in itself causes behavior and personality problems in some patients. Also, is he on any medications and when is the last time he has been checked for any illness's? Some older people are just grumpy (i'm learning this since being a member of this forum).

Connie, if the family cannot do something for his behavior, you just walk away.Possibly they will have a neurologist see him or even a psychologist to try to get to why he is so grumpy.Many times their bark is bigger then their bite.