The smallest bat found in Estonia. They grow up to 4.5 cm in body length and only weigh 3.7–4.8 grams. Their back, ears, and patagium are dark brown; the stomach is slightly lighter. They mostly live in parks and broad-leaved tree forests, but can also be seen near residential buildings and above waterbodies, at 3–5 m from the ground. Common pipistrelles fly at the height of tree crowns and treetops; their flight is peaceful and slow. Often, they can be seen flying in a completely straightforward manner above roads and clearings while hunting for smaller insects – mosquitoes, midges, and butterflies. They become most active after sunset. Then, they hunt for 20–30 minutes and return to their nest to wait for the early morning. In the daytime, they look for shelter in tree hollows, under roofs, and behind shutters. Before farrowing, female bats come together in colonies, which are usually located in tree hollows. Male bats spend this time alone or in small groups. They are endangered by chemicals used for insect control. Under protection (protection category II). More than 65 species of mammals have been registered in Estonia, 14 of which are bats or Chiroptera. There are about 500,000 bats in Estonia. In Tallinn, their most important feeding places are Kadriorg Park, Pirita River Valley, Raku lakes, the area surrounding Ülemiste Lake, Astangu, and Rocca al Mare.