Cats need companionship and a sense of security when their guardians go out of town, just like dogs do (that goes for birds, rabbits, hamsters and all other animals as well). Cats may seem aloof or that they like to be solitary, but they are just a little different than dogs are, don’t show their emotions as obviously. They can feel lonely, insecure, or even abandoned, if left alone for a few days. Some cats will become stressed and stress can cause illnesses over time. They have similar mentality of a toddler (and kittens like babies) so please make sure that it is not only safe in your home for cats, such as no open electrical outlets, or windows without screens, or dangerous things they can chew or swallow, but also that someone will come by and visit them and, of course, feed them, and clean their litter box.
Your cat(s) will be calm and happy when you return from your trip when you have a friend, relative, neighbor (must be trusted) visit the cat(s), instead of being stressed and anxious. My normal visits are one hour, but I often stay longer than an hour, and sometimes am asked to stay overnight. I have seen cats left alone for two days who were so unhappy about it; and I have seen the difference it made when i visited every day with a trio of cats rather than every other day. Another thing to consider is if something happens to your cat when he/she is alone, there is nobody there to help him for two days. It could be a matter of life and death, such as a urinary blockage in a male cat! I know of a previous client who almost lost her cat in this way.
After feeding the cats and cleaning their litter box(es), many cats appreciate some interaction, such as playing, brushing, or even just talking to them and hanging out with them, keeping them company. Because they are alone perhaps 23 hours in the day when the sitter visits for an hour. Many people ask me to visit their cats for half an hour, or come by to feed Matilda and clean her box - no playtime? No time for anything else? That is not what I do, as a professional pet-sitter. Even shy cats who hide come out and want attention, if they don’t feel threatened by their pet-sitter.
Kittens especially will want to play and cuddle. Also with kittens under six months old, they should not be left alone for more than 5-6 hours. Kittens are very curious and mischievous, and can get into trouble in no time.
Cats are territorial, so they are content to stay in their own home, rather than go to another home, or be boarded at the vet. Next time you go away, consider hiring a professional pet-sitter to visit your cat (or parrot, or turtle, or gerbil) in your home, someone who takes their job seriously.