Evil gerbil- please help.?

You should start slowly. First of all, it's important to understand that it's not the gerbil who is evil in his eyes, but it thinks you are evil, so you need to show it that this isn't the case. You should leave the cage open and stick your hand in there and just let it go up to it. When it does so, don't grab or make sudden movements. It's important to never grab your gerbil if he is showing signs of nervousness, if you have to chase him around to get him, don't grab him. Keep your hand in the cage for a while everyday and he will get use to it. you can also begin to feed him, food is a great way to reure a gerbil in distress, and shows them that you are his friend. Continue to do this. It's also important to not get angry at the gerbil, or avoid touching him. If he knows that biting you will make you go away, he will obviously continue to bite you, so you will need to have patience and find a way to familliarize him with your hand without getting bitten. It's going to require lots of patience, but in the end it's very rewarding, so don't give up!