I bought 1000 superworms and put them in a plastic tub with alfalfa rabbit pellet bedding (like the pet store next to me uses in their bin) and some apple slices on top. the container is approx 18 x 26 and the bedding is about 3 inches deep. I put 6 apple slices on top of the bedding. It is at room temp about 74F and all the worms are coming to the top and dieing. What am I doing wrong?