I suppose that could happen. One idea is that you just hide them at one time, so even if they see one they won't see the rest if they get distracted eating the other. Over time they'll learn food is around for them to find.

One trick I do is to fill and hide the mice when he's eating his wet food. Nothing will distract him from that! But he's also learned that I do fill them, but won't just give it to him. He might try a quick snack when I'm filling one up but otherwise knows he'll get them somewhere else later.