Twice now I have purchased silkworms and twice now they keep dying. The first time within a week they were all dead. So I thought I would try again and I just received some today and I put them in a large plastic container and I just came home from work, 8 hours later and already about 8 of them had turned black and went real mushy and gross. What is the trick to keeping them alive? My chameleons really love them but at this rate it is to expensive if I keep killing them.