Our neighbour Bat
Bats have been roosting in man-made structures such as buildings for a long time. Maternity colonies of bats can be found in attics of old buildings, e.g. churches where they are safe against predators. Such places are used by different bat species, mostly those sensitive to outside temperature.
An intensive development of urban areas in 60s to 80s of the 20th century resulted in creation suitable roosting sites for bats in buildings. Especially prefabricated houses provide good roosting opportunities for bats (in crevices, ventilation holes, attics, etc.). These places are very similar to their natural roosting sites and are well protected against predators. The most common bat species living in buildings in Common Noctule Bat (Nyctalus noctula). Major part of its population in Slovakia occurs in buidlings in cities also due to the fact that its natural sites (tree hollows) are rapidly dissapearing.
The most common bat species in buildings
Common Noctule Bat (Nyctalus noctula) is the most common bat species occuring in prefabricated houses. It is the largest bat species in Slovakia, body length 6-8 cm, wingspread 35 cm. Its hair colour is rusty-brown, wing-membrane is dark-brown. The species is active already at dusk and has a strong voice. It flies in an open space high above the ground. In autumn it can be seen flying already in afternoon, during a daylight. The most common roosting sites of this species are ventilation holes and crevices in buildings. It occurs there especially during autumn and winter, very often also during the whole year. The species often lives in big colonies of several hundreds of individuals.
Pipistrelle Bat (Pipistrellus pipistrellus) is the second most common bat species that can be found in buildings. It is a small bat, body length of 3.5-5.0 cm and wingspread 20 cm. The body is of brown or grey-brown colous. It can be often seen flying in small groups of 3-5 individuals nearby street-lights. Young bats often fly into flats when looking for suitabel winter sites.
Bats are not dangerous
Bats as well as other species have their specific parasites. However, these are not dangerous to human. Bats can serve as transmitters of e.g. rabies. However, bat species occuring in Slovakia do not attack people in purpose and accidents with people are very rare (e.g. when experts-biologists must manipulate with bats).