What happens when a cat suddenly becomes grumpy?

There are many reasons for cats to be grumpy, such as the environment they have been brought up in, or whether they are born that way. Sudden changes in the environment, such as a sudden relocation of the litter tray, moving house, etc. Sudden addition of people or cats or dogs to the household, etc. If two sexually mature cats at home may behave in this way during the rutting period, and suddenly become anxious and attack people indiscriminately for no reason, then owners should be aware and make sure their cat has received rabies vaccination.