If your cat’s behavior problems include ankle biting, your cat may have predatory aggression. In other words, your cat is not getting enough play and exercise to simulate their hunting activities in the wild. Because your cat doesn't have very many moving options inside the house, they go for your ankles.
Here are some tips to discourage this behavior:

When your cat attacks or bites your ankles, give them an appropriate toy to play with, like a mouse on a string. This will simulate the experiences they would have if they were hunting in the wild.

Fishing line toys that you reel in are also an excellent choice. Some people simply tie a toy onto a piece of string, and then tie the string to their belt, dragging the toy along behind them.

Often, just giving your cat enough playtime and exercise will cure your cat of this and other cat behavior problems, so don't forget to play with them every day.

Many experts have found that these cat behavior problems frequently disappear as the cat matures past two years of age. Be patient with your cat and keep these helpful hints nearby to discourage bad behavior at a young age.