YLL, my rats jolt sometimes too. I tried looking it up as well, and couldn't find anything Just a few hard jolts, it lasts a minute, and then leaves. Not sure why, I talked to a vet about that a while back, he had no clue what it was...

I asked the vet for ILBF, he said that it's hard for him to know if something is wrong unless he can check the rat out for himself, but he said it could be caused from stress/ anxiety, being scared, cold, or it could possibly be a symptom of an illness..

Good luck