If a trap closes about 3 or 4 times, it dies. The plant then brings up a new one. Now what I meant about the flower was this. Most plants get their nutrients from the soil, the minerals in the water etc. Flytraps get theirs from insects. While they do gain a lot of energy from this they are still relatively weak creatures (hence why you don't see traps the size of your head) Basically when they begin to flower they use up almost all of their energy in creating that flower, meaning that after it's flowered there is a good chance the plant will die. It's very important to make sure that if you see the flower and you don't know how to properly care for a flowering trap, that you need to cut the flower stem off so that it has enough energy to survive the season.
Now as for the question about what insects. It likes flies, it can eat spiders, although it's not very good for it. Ants are a big no no along with anything that eats plants, like beetles and other things.
