More than 1,000 bats flew out of a small wooden building at the Ķemeri National Park.
Most of these were Pipistrellus nathusii, which is one of the most common bat species in Latvia, which often makes its homes in buildings.
Bat researcher Gunars Petersons said that what he saw in the National Park was an unprecedented observation in Latvia.
Up to now, 200 to 400 female bats have been listed in the largest known bat colony.
“In this case, it is likely that some were babies, barely able to fly," said Pētersons. "The home owners are informed and will not disturb the bats until they have left."
