The Whiskered is a small bat with quite long, shaggy dark hair on the back. They can sometimes have golden highlights. The hair on the underside varies from dirty grey to light grey. The ears slightly curve backwards and the tragus is long, thin and sharp.

Forearm 30 - 39mm / 1½ inches
Length 35 - 50mm / 1½ - 2 inches
Weight 5 - 9g / 3rd oz

These bats are the gentry of British bats as they are often found in 'gentleman's residences' in country estates. They roost on the exposed rafters especially the ridge beam with lines of droppings below. They are not found at the gables end as much as Pipistrelles or Leisler's bats.

• Emergence: usually within half an hour of sunset and earlier than Daubenton's bat and Natterer's bat. They could easily be misidentified as Pipistrelles. Compare emergence to other N. Irish bats.

• Flight: forages 1.5-6 m above the ground. Rapid, agile and weaving.

• Habitat: parks, meadows, flowing water, woodland and gardens. Often found along woodland paths where it tends to hug the edges, preferring to forage in dense parts such as the tree crowns. Along edge habitats it tends to fly to and fro, turning in wide arcs when it finds a dense patch of insects. Never seems to fly high up in the open air. Will occasionally glean from foliage.

• Heterodyne: Similar FM sweeps to Daubenton's and Natterer's bats. Their echolocation call is strongest at 45 kHz. In comparison with Daubenton's bats they emits pulses with a much more irregular rhythm and are quieter.

• Time expansion: Fast pulse repetition rate although not as fast as Natterer's bat. The rate is more irregular than Daubenton's. See and hear time expanded call.