Plans to demolish more than 80 homes in County Durham have been halted because of fears over a colony of bats.
Proposals to knock down 82 houses in Easington Colliery were put on hold after tests revealed evidence of the animals in the empty properties.
Easington Council said it had delayed the work until May, when the results of further tests will be known.
Bats are protected and it is illegal to intentionally kill or injure them, or destroy breeding places or roosts.
Ian Morris, Easington Council's head of housing strategy, said: "English Nature require us to undertake a survey on buildings that are being knocked down to ensure that we do not put this protected species at risk.
"A survey was carried out in January and we were advised that work could go ahead, so plans were put in place for demolitions to start.
"Unfortunately we have now been advised that as there is a high risk that bats are roosting, an emergence survey is required.
"The council has therefore had to delay the start of the demolitions until the results of the emergence survey are available, which should be sometime in May."