Kitten and ferret is this normal?

I have a 3 month old kitten and a 5 month old ferret. I got the ferret about a week ago and I've seen a change in my kitten. Things the kitten would not do, or go into before, you just see two fur balls going into things, pulling things out, its crazy. Before he would sleep in my room, but now he sleeps by the ferret cage. I have caught them sleeping together in the cage and when I separate they crawl back to the door. also with the ferret, I put her on the top of the cage in her hammock and she will wake up go down stairs and sleep by the door, where the kitten sleeps now on the other side. The ferret only sleeps in the hammock and stays there if the kitten climbs to the top of the cage to sleep there. When it get to uncomfortable for the kitten he gets down, but sleeps near the cage, when the ferret notices he is gone to the floor, she goes to the bottom too. Its cute, but very odd. they share each others food, water, bathroom. They run around chasing each other and strings on people's pants. I put the ferret away, both pull on the cage door with their teeth, then give me the "party pooper stare". lately i've been letting the kitten sleep in the cage, b/c when i put the ferret away the cat meows, scratching the cage door. Has this happened to others. I know both where taken away from their litter, and like the same things, but this is really weird. They even sit under the couch waiting for feet to go by so they can jump out and attack toes. They are really attached to each other, my cat cleans my ferret. Is this normal?