These house geckos were introduced to florida a long time ago. I lived in Jacksonville in '83-84 and there were plenty around then. Any non native species has an adverse impact on the environment. The impact on this species is probably minimal with regard to other herps, since they are nocturnal and exploit a niche that is otherwise neglected, by the native lizards. However, they probably impact moth populations or whatever other nocturnal insects they are eating. Which to most people is a good thing.