Okay, so, I've had my male cat since he was around 7-8 weeks old and it's almost been two years. He's quite quiet normally, so the behaviour he had been displaying is odd. The other day, I went out and ended up coming home with a rabbit who is 13-14 weeks old. My cat was quite curious about the rabbit and kept sniffing the cardboard box (which had the rabbit and some hay in while I was setting up his cage). After the cage was set up, my cat came in and sniffed the rabbit, before meowing. He didn't seem to have any violent intentions, so I brought the rabbit out for a closer look. I let the rabbit explore a little and my cat wasn't too far behind. The cat ended up letting out loud meows every time my rabbit moved away from him, and he also started to groom the rabbit when they were sitting together. When the rabbit was on my bed and the cat was on the floor, he had to reach his body up and seemed to always have the rabbit in sight, and would stare at me when I was going to pet the rabbit. Now, my cat keeps meowing at the door constantly, trying to get in. I shut him out because I have my rabbit's cage open in my room, and the cat can't stay in here forever, as he needs to eat and drink and use his litterbox too, which is all downstairs. But even though I don't know what he's doing, there's another part to the behaviour that really concerns me. If he's sitting with the rabbit and grooming him, but then the rabbit tries to wander away, the cat will let out a really loud meow and then go to bite the back of my rabbit's neck. This doesn't seem normal. Does anybody know what my cat is doing??