Ok the batch of fry I have are doing fabulously (did I say that). But I have 4-5 runts that are acting peculiar. there heads up and trying to get to the surface of the tank they get there but just stay there with there heads up toward the surface. When I place my finger near them they skoot away and seemed to swim normally but immediately go back to doing the same thing. Are they just weird or is it something else?