Depends on the males. They might chew their own caudals off, in an attempt to fight something...or they might stress themselves to the point of letting a disease overtake their immune system. Then again, they might be docile enough to flare awhile, then be ok with it. There is no set rules when it comes to how a betta might act. If it too much for them, you can always add a colored divider that just slips in, and you could remove it awhile each day so they get exercise, then give them some peace by blocking their view again. Personnally, I think the last option would be better.
