Abstract
Different species visit or exploit cavities for survival or reproduction, including human-made boxes. Ants and Paridae from mainland southern France share artificial boxes at different life-history stages. Colonies of the ant Crematogaster scutellaris occasionally prevent Paridae from roosting or breeding in boxes and therefore might influence nest-site selection in avian cavity-nesters. Factors that influence coexistence or avoidance in bird-ant interactions in the Mediterranean region are discussed