Night crawlers love areas where they have things to eat and sufficient moisture. To remove them quickly, put a weed and feed fertilizer on your lawn and it will kill them. Worms are good for your lawn though.
Night crawlers, (worms) are good for the soil and something most people want. However, if you are determined to get rid of them, you can pour salt on the ground. This will make them go away, as well as destroy your soil.