Read this series when I was 10ish. I'm 31 now and just spent an hour perusing the Animorphs Wiki on a nostalgic whim.

Question... how does Visser Three keep Alloron as his controller, when Visser Three has to leave his ear every three days to bathe in the yeerk pool? The wiki says involuntary controllers are kept in cages, but it's hard to see those posing an obstacle to someone with morphing capabilities. Alloron could turn into a giant monster and wreak havoc. Yeah, he might get killed, but he makes clear he'd prefer dying to being a slave forever when he begs Ax to kill him.

So how do the yeerks keep Alloron under control? Do they render him unconscious before V3 leaves his ear? Threaten worse punishment if they recapture him alive? Some special technology? Or is he just too psychologically broken to ever revolt?