Strange behaviors

Question
I've had cats all my life.  But, my daughter's cats really have me baffled.  She has 3, 1 of which is the offspring of one of the two older ones.  Suddenly the two older cats are hissing and picking fights with each other and the younger of the 3.  At least one of the two older ones has quit using the litter box and is using my granddaughter's room instead.  We've had to shut up her room to keep the cat out of it.

Second issue is we can't seem to leave food anywhere unattended.  The grandkids will pour a glass of milk and turn to put the carton back in the refrigerator only to turn and find a cat drinking their milk.  Bread left out, but still packaged, is ripped open and the bread eaten.  I brought home leftover hotdogs and hamburgers a couple of nights ago from a cookout.  The food was in zip lock bags that were sealed.  Within 5 minutes, the cats had the bags drug into another room, a hole ripped into it and eating it.  I might mention, the odd behavior always seems to be the two older cats and mostly one of them.  I might mention, the cats are only 2 years old.

Any suggestions?  None of them are fixed yet and they are inside cats for the most part.

Answer
Shere -

I think you have answered your question in your letter.  Much of the fighting is most likely due to hormonal influences.  Have your cats spayed or neutered as soon as possible and you will most likely see a change in their behavior.  If you wait too long to have them altered their behavior will become habit and you may have a lasting problem.  

Secondly, cats tend to become fiercely territorial. If they are living inside your house you will need to have at least four litter boxes.  The American Association of Feline Practitioners recommends that cat owners have at least one extra litter box per the number of cats you have; if you have three cats then you need to have four litter boxes.

Place the food bowls in several places in the house.  You may want to have one bowl in a secluded space for the weakest or shyest kitty.

The cats are eating your food for no other reason than because it is there. If the food is available then some cats will eat it.  You can also try behavior techniques such as spraying them with water if they are on your counter or tables.

Best Regards,

Charlotte Sherrell, DVM