"It would be very disgusting. Nothing's that gross, therefore.." It's a sound theory!

He has never heard of such an improbably nonsense filled idea in his life as putting animals in balls, unless it's hamsters.

"They do what?"

Pokeymonsters. In balls. "Are those ... hamsters of some kind? Small rodents?" What else would be put in a ball and left to do their own thing? The possibility that most pets on the train are small self contained little cages of mice was almost but not quite reassuring.