But at Burry Port primary, in Carmarthenshire, doing this threatens the health and safety of children: essential restoration work has been halted by the discovery of nesting swifts. Under the Wildlife and Countryside Act, 1981, the birds cannot be disturbed from the eaves, despite collapsing masonry in all three buildings at the 100-year-old school. .
David Davies, head of Burry Port, said: "Parents are very concerned. If repairs are delayed, it would affect the health and safety of the children."
Repairs cannot start until the birds migrate. That may not be till the end of the summer, too late for building work to begin.
Stephen Thompson, Welsh officer of the Royal Society for the Protection of Birds, said: "In this instance, birds have to come first. But we'd like this to be something kids could focus on, in project work."