Welcome to the forums Jennifer! There’s a few pieces of information that’d be helpful to know:

1) How long have you had them?
2) How old are they?
3) Are they neutered?
4) How long have they been together?
5) Have there been any changes in their eating and pooping?

— I will beat every BB member to the chase and mention that if neither of them are fixed and they are young (less than one year old), it’s very risky to have them together. Under the circumstance that they are both unfixed and young, this means that they may not have had the hormone surge that comes with maturation. When the hormones do present themselves, lovable rabbits who used to groom and cuddle one another become killers and try and attack each other, purely out of territorial instinct. So please be wary if this is the case. The best advice is separation until they’re both fixed. Also, if they’re very very young, unless you see testicles there, it’s always possible one is actually a girl, in which case, when hormones hit, mating can happen in less than a minute.

…. But that aside, it’s good to get some opinions when your rabbits are acting out of the norm. There is a phenomena most rabbit owners run into with their growing rabbits, which is simply the rabbits “mellowing out” with age. They start getting a regular sleep-wake routine, versus when they were young and they adhered to no real schedule. Rabbits tend to be sleeping/resting in the morning until late afternoon, so this may be it.