If they have no tank mates, I'd just drop the food in and let them figure it out, really. Its not like some thing else is gunna get it before the do
I use a thick (nearly 1/4" diam?) bamboo bbq skewer to target feed bloodworms to my ADFs, one worm at a time. It's working really well for me...
I cut off the pointy end of the skewer, and made a short slit up the stick along the grain, maybe 1-1/4" long (kind of like if I was splitting the skewer into halves, lengthwise, starting at cut end). That slit stays closed enough on its own, but can be pried open with tweezers, which I use to load the skewer with 1 bloodworm at a time. So when I lower the worm on/in the skewer down to the waiting frogs (mine come out at feeding time, 3 strong taps on the tank rim), they can yank the worms off the skewer easily, and I don't have to worry about dropping it too early or holding too long with tweezers. And the top of the skewer stays above waterline, so no fingers in tank.
Agree!! My guys come out and inspect/strike at almost anything new in the tank. If I use my trusty skewer to move things around, or pick up a stray piece of java moss, they go after it. They also go after they vacuum/siphon tube, so I have to be careful when cleaning.They soon learned tube = food.