This morning a swift flew into my son's room through the narrowly half-opened window.
It sat on the desk, so soon we could catch it and then let it out from the balcony.
Many swifts have nests in small hollows in the buildings where we live.
The Common Swift (Apus apus, Jerzyk in Polish) is a small bird, superficially similar to the Barn Swallow or House Martin.
It is, however, completely unrelated to those passerine species, since swifts are in the separate order Apodiformes.
Swifts have adapted more commonly to human sites and build their nests in all suitable hollows in buildings, under window sills, in the corner rafters of wooden buildings, in chimneys, and in smokestacks.
A swift will return to the same nesting site year after year, rebuilding its nest when necessary.