Korat kittens & cats in Lancaster, Pennsylvania

He's about 2-3 years old and was vaccinated shortly before we got him, his chip is not setup but he has one. He's not aggressive but it seems like his previous home didn't properly socialize him, so he's really awkward with how he's been hanging around our cat. He steals her food and bullies her out of her cozy spots, but he isn't aggressive in doing that so I think he just doesn't know any better. He's litter trained, but doesn't groom himself well and will track litter EVERYWHERE. He will SCREAM for food every 6 hours on the dot and after about a month of having him he also screams to go outside between 2-6 am even though we've never let him outside. He's not a BAD cat, but I just worry that he's stuck in his ways, and the disruption he brought to the house was a lot more than we anticipated. I'd rather not take him to a shelter if possible.