During the last decade, wind turbine construction has become an issue of paramount importance for bat conservation. Several hypotheses have been proposed to explain why bats come close enough to the spinning rotor blades to get killed, some of which assuming that bats explore wind turbines. We test the hypothesis that the forest species Barbastella barbastellus explores tall towers (lattice towers). Echolocation calls were continuously recorded over a one-year period. At two study sites we analysed temporally linked consecutive echolocation recordings between neighbouring automated acoustic devices (batcorder) which were installed at 3.5 m (ground), 20 m (canopy), 35 m (above the canopy) and at 50 and 80 m (open airspace). We assigned 7-10% of all contacts to vertical movements. Bats moved along the lattice towers at heights of between 3.5 and 20 m at both sites and between 20 and 35 m at one site. Although the extent of this explorative behaviour may have been underestimated due to limited acoustic detection distance, and although we used a lattice tower (most wind turbine monopoles are made of a different material), the almost complete lack of echolocation calls above 50 m at the first study site and above 20 m at the second study site makes it unlikely that explorative behaviour may expose B. barbastellus to significant risk.