We evaluated five species of the genus Ambystoma in laboratory aquaria to quantify the effect of other larvae on microhabitat use and activity. We studied microhabitat use by partitioning containers into microhabitats that either contained or lacked refuges and recorded movement to determine activity. All five species altered microhabitat preferences and activity levels when they shared tanks with larvae of most species. The smallest species (A. laterale and A. maculatum) spent the most time in the vegetated chamber, used the vegetated chamber more often, and decreased activity in the presence of potential predators. When species were paired, both species usually changed their activity and use of microhabitat in opposite directions. These behaviors may be important in maintaining coexistence among species by reducing interspecific aggression and intraguild predation.