Their pellets. In our house we refer to pellets as bunny crack. Thumper's breeder feeds the same pellets as I use so he has always had them. The two girls were on a different pellet and I slowly switched them over.
Thumper goes the craziest but the girls are almost as bad.
When it is time for pellets Thumper runs all around me like a crazy guy as I walk to get the pellets and as I cross the room to his cage. When I get close to his cage he then hops around inside of it and outside of it, switching between hopping and periscoping. I then have to try to time it right to quickly get his pellets into his bowl. If I don't time it right he hits my hand with his face and pellets go flying or he knocks his dish down which hangs on the side of the cage.
His pellets are stored in a plastic storage box and I can only crack the top open or he will dive in and start eating. Before I kept them in a corner that was blocked off from him between his cage and a chest freezer we have in the room and at times he would climb the open door to his cage trying to get to the pellets. Luckily he only did this when I was getting pellets out so I have always been able to lift him off the door.
And he doesn't eat his pellets he crazily scarfs them down. I'm afraid some day he will choke. And yes, I do feed him enough he just acts like he's starving. What makes this all the more shocking is that for the rest of his day he typically just lays around when not eating or grooming.
The girls also start zooiming around like crazy when I get the pellets. They will also run in and out of their cage, they run head first into their bowl as I place it back in their cage. They also at times will run into me or into each other. They did not react like that when I first got them and they were eating different pellets.
One thing that is a guarantee though...I never, ever have trouble getting any bun back into their cage. I just have to use their pellets.