My cat is a 16 months old, female, domestic short hair (grey). I got her when she was 9 weeks old.

When I first got her she ate normal (recommended) amounts. When she reached 3-4/mo she started to eat human food, food I left out, she would eat all of it. I have had cats in the past but none with behaviour like hers.

The past 10 months it has gotten really bad, she eats all the cat food I give her and then steals food from the cat who lives upstairs everytime we open the door. She will steal food out of my hands and even my mouth! If I leave to go to the bathroom and forget to bring the bag of chips with me she will wait until I leave and then eat it all. She goes through the trash can looking for food as well.

I just dont get it. I feed her more than enough, what is wrong? Does she has some kind of deffiency?

Please help, thanks.