We adopted two cats, a boy and a girl. Their age is something between 1 to 1.5 years, I'm not sure, the shelter is not sure as well.
It's now near a week that they're here at the house, at the beginning the girl which looks a bit older was fine and discovered the house really quickly, while the boy was always under the bed in a dark space sitting and just getting out only for peeing and eating and returning under the bed again, from the first moment it was obvious that the girl doesn't like the boy, whenever he passes near to her she makes sounds for the fight and the boy runs away to his dark house. She was like 'This is my territory' cat, and the boy is like 'Would you please let me play?' cat, he scares of her very bad, which is sad.
Now after few days it's a bit different, the girl is getting sad while the boy is getting happier. The girl was really open to being pet by me while the boy always run away from me, now they're both run away from me. They can't play with each other, and when the boy is playing she gets mad at him, he scares and hide under the bed.
I know it's a week they're here but I'm not sure what's wrong with them and what is the solution.