How many hours of Sun does it get? Are you growing it indoors? These aren't indoor plants.

Well yes I am keeping it indoors, but that is because I am in New York, and it gets pretty cold outside here, and im not really sure what temperatures it can survive in. Also, I only water the plant when the soil starts to dry, after I water, the soil doesn't look like it is muddy or soggy.

Well I am in N.Y. as well. Mine go outside in May until first frost. In fall / winter I put all mine in zip lock bags then into the fridge until April.

Well what I want to know is, should I do anything about the plant? This is its last trap and I don't know how to feed it, when I put a dead mosquito in its mouth, it didn't respond, even after poking the inside of its mouth with sticks.

Flytraps will not eat dead insects. Once an insect is trapped the bug needs to move around more to trigger the trigger hairs a second time before it will seal up and eat the insect.

You do NOT have to feed carnivorous plants. They get most of their energy from SUNLIGHT. That is why they are not indoor plants. They NEED 6 hours or more of sunlight a day during the growing season.

Alright, thank you tommyr! So you think that the reason the trap is growing black is because it doesn't have enough sun?

Traps don't last forever. It may be that it's normally dying but not enough Sun is a possible cause as well. Putting it under 6500k florescent lighting would be helpful IF you insist on growing it indoors.