Teaching your cat to use a litter tray requires a little patience. The first thing to always remember is that litter trays need to be kept clean, otherwise your cat will prefer to do her business somewhere else (like on the carpet). Clean your cat's litter tray every day, rinsing it with water and replacing the old litter with around an inch and a half of fresh litter.
It's best to place the litter tray in a quiet spot that is well away from where your cat eats and drinks. The best places for litter trays tend to be more secluded areas of the home, like the laundry room or a spare bedroom.
You should place your cat in the litter tray after she's eaten until she eventually associates that spot with going to the toilet. After some time, she will begin going to the litter tray of her own accord. Whenever she does this, be sure to give her plenty of positive reinforcement through praise and reward.
During the learning phase, it's important you don't get angry at your cat if she has an accident, as this will only make her afraid. Instead you should allow her to sniff the area where the accident took place and then gently place her in the litter tray.
After your cat has become accustomed to using the litter tray, you may want her to begin going outside to go to the toilet. Many kittens learn to do this at an early age from their mothers, but others require a little more encouragement.
Start by gradually moving the litter tray closer to the door, and eventually putting it completely outside. It may be a good idea to use a cardboard box as a little shelter for the litter tray to make your cat feel more secure. Once your cat is comfortable using the litter tray outside, you can take away the litter tray altogether. Make sure that you take your cat outside if she's showing signs of needing the toilet, like meowing or sniffing around near the door.
When bringing a new cat home for the first time, it's best to keep it in a single room for the first few days. Your new cat will become familiar and secure in this environment, giving her a safe place to retreat to when you eventually introduce her to your other cat and the rest of the house.
To introduce your cats to one another, start by placing a piece of the new cat's bedding near the resident cat, and vice versa. This allows them to become familiar with one another's scent. Once this has happened, you should start leaving the door open so that your new cat begins to venture elsewhere around the house and eventually meets your resident cat face to face. The initial encounters are usually a little hostile, involving some hissing and arching of backs, but this is completely natural and you shouldn't interfere unless you witness serious physical aggression. After a while your cats will begin to tolerate one another, and may even become good buddies. But remember that there is no cut-and-dried way to train two cats to like each other.
Young cats are especially playful, but may need to be taught not to scratch or bite when they're having fun.
One of the ways to cut out this behaviour is to 'play dead' whenever your cat gets a little too aggressive during play. Simply walk away and ignore your cat whenever she bares her teeth or claws, and she'll soon learn to be less rough.
If your cat continues to be rough, try filling up a spray bottle with water and spray it at her whenever she uses her claws or teeth. She will soon associate her feisty behaviour with the uncomfortable sensation of being sprayed.
Finally, you should always remember that cats are natural hunters that instinctively like to stalk and pounce on things that move. It's important therefore to give her a hunting outlet, otherwise she may start practicing on other pets or even your children. There are hundreds of toys out there that will help satisfy your cat's predatory instincts.