Does your guinea pig...?

One of my guinea pigs Bart always runs as soon as i put him on the floor. When i hold him, Then he scrambles sometimes trying to get on the floor even if I Just gave him floor time!! Is there a reason for this? And how much floor time should I give him? My other guinea pig Mouse always lets me cuddle him and when i put him on the floor, he starts oinking like crazy. But when I pick him up again, then he calms down and sometimes go to sleep. Why doesn't he like the floor? Sorry for all the questions, but please answer!!! Thanks!!!