I can tell you that at work I like to really baby all the little critters and make sure every single one of them is happily munching on something when I feed. #1 - being torn away from wherever they're from and sloshed around in awful little bags in the dark for many times over 24 hrs I figure they really NEED the extra coddling!! #2 - it really lets me know about each and every animal so that I'm alerted right away if something isn't right so I can see about fixing it and I can tell my customers exactly what's going on with each one so that they can make good choices.
First I toss in whatever I'm feeding the fish that day then, while they're happily racing after the goodies, I carefully drop a little something down so that it falls as close as possible to right in front of each invert, then I stand back a bit and study each animal. Is it eating? Is it eager to catch the food? Are any not getting enough? Does it seem shy or scared and just darts out of hiding to nab something then race back to hide?
There's a ton you can learn about all your pets, aquatic and otherwise, just by standing back a bit and really studying them!