so zooky has an FN and every night i hear him crying. it sounds like hes running on his wheel (silver surfer) and falling. im not sure because everytime i go and check hes laying down on one of his shelves acting normal. i guess the silver surfers running surface is slippery and a little small. is crying at night normal? if not how can i figure out what hes getting hurt on? and if its the wheel what can i do about it?