Geckos are small reptiles which feed upon insects and spiders around houses. While the insect eating can be a positive side effect of a gecko infestation, they can become as much of a nuisance as the bugs they eat if their numbers become too great. By taking the proper preventative measures, you can control the gecko population, and encourage them to move on to another house.
Prevent geckos from accessing your house by ensuring there are no points of entry from outside. Check all your windows for gaps, and use sealant to close them. Patch any holes in window screens that the geckos can crawl through, or replace damaged screens.
Clean your house, particularly near your trash. Geckos eat insects, so by cutting down on trash which attracts the insects, you remove the geckos' food source, forcing them to find a new house.
Spray insecticides to kill off any insects in your house, once again removing the geckos' food source.
Lay mothballs in the corners of rooms and cabinets. The chemicals in the mothballs are an irritant to the geckos.
Introduce a cat to your house. An older cat that is known to be a hunter is ideal, but young cats have a natural instinct to hunt and can also be effective. Older cats that have shown an aversion to hunting, and are not known to try to catch mice or birds, are less likely to be successful at removing geckos.