Hey there. Well my little ally's won't keep their mouths open if some one is around and they can see them. They will not eat in front of some one. But I'll sit at my computer across the room and watch them or stand on the other side of the tank to where they can't see me because of their little hiding rock is in the way. But they eat probably about 3 to 5 dozen guppies a week between 6 hatchling ally's. And the guppies are live swimming around the in tank. Just give them time and space. Like some other people have said they are kinda shy. They like to hide. Just my two cents.