I have 4 a black convict, white zombie, and orange, and a blue and purple striped one well ive have the white zimbie for a little while and just got the other 3 the uhh seem to be soing well together but when I out the 3 new inesin the white one started vibrating! & he did it like 3 times it was crazy I was just wandering what that was ive never seem him do that b4