The European Free-tailed bat is a large, robust bat with a wingspan of 400-450 mm, long broad ears and velvety black-grey fur. Another characteristic is its tail, which extends beyond the membrane and has a sensory function.
This species occurs in mountainous regions and urban areas and is known to forage fast while in flight. Its diet comprises of flying insects: moths, hawk moths, seasonal Diptera, lacewings and beetles.
T. teniotis is known to be sedentary and to dwell in rock crevices in cliffs, caves and bridges during both summer and winter.