Bearded Dragons are far-sighted. They do not see especially well, up close. When you release alot of feeders around a beardie, often you will see them back up. This is to see the prey better.
Also, the beardies 1st rule of thumb is: If it moves, eat it. When there are alot of critters all at once, it can be overwhelming and stressful on the beardie. They see the movements, but there are so many, they cannot readily choose just one. They don't know which one to go after first.
Often, they will sit and look for a while. They finally pick one and chomp, chomp, down the hatch!
It is better to feed a smaller amount at a time, or hand feed if they allow it.
Emerald