First, I think we need some squirrel briefs. I think they'd be educational. Trying to get a squirrel into them would combine exercise, dealing with frustration, first aid, and probably rabies shots. Fun all round!
Second, I am trying to think of new low-mess educational activities that the boys won't turn into WWIII. Stringing big pasta on yarn might be okay. Sorting shapes might work. Cutting out food shapes from flyers and gluing them onto paper would probably work.
Never Underestimate Boys' ability to Turn Everything into a Throwing/Hitting Game, that's my motto.