My treefrogs generally sit and wait for food to come close to them. Then it's an all-out dignity-abandoning attack with little to no regard for how mashed up their fingers and toes get (see first 2 photos below). The front hands are also used to help cram the food in, and the eyeballs go squishing into the skull to help swallow the food. If they miss the lunge, they'll usually just go back to sitting and waiting for another opportunity. There is the occasional spying of food from across the tank then slowly walking closer, but it's usually sit and wait, they're very patient.
Probably 80% of the times I see my treefrogs move is when they're eating, so in terms of the frogs 'doin stuff', it's always fun to watch. They aren't like cats who will run randomly in circles for no apparent reason.
I never feel bad for their food items. Circle of life and all that. Besides, I do breed my own crickets and maybe 20-30% of those get to die of old age after having spent their lives eating and breeding to their hearts content. Some win this jackpot, same get sacrificed. The odds are even better for my mealworm colony, very few actually make it into my frogs (but these occasions are much easier to photograph than the cricket eating). They've come to accept this arrangement and will sometimes offer brave volunteers to jump down the frog-beasts throat (3rd picture below).