Bats can play havoc with construction schedules if found on site. Building’s blogger spent a balmy evening in Regent’s Park to find out more

A bat walk for the press and DEFRA in Regent’s Park brought out the wag in everyone on Monday. “I heard about this, and thought I’d give it a flutter,” said a DEFRA official who specialises in Scottish farming and being droll. “I’ll be bat,” said another, who was nipping into a local pub’s toilet.

We were there after The Telegraph diarist Same Leith declared in a column “Shoot a bat for Britain, I say”. The Bat Conservation Trust was not impressed, so set up this trip for the press.

When we got there Katie Parsons, BCT's Head of Biodiversity, handed out bat detectors (amazingly, such things really do exist, although I was disappointed that there was no clingy superhero outfit in the ‘bat packs’ the BCT handed out). These allowed allowed us to hear the bat’s sonar and the raspberry sounds they make when gobbling insects. After an hour of listening to the engaging chirps of Daubenton, Noctule and Pipistrelle bats Leith’s mood mellowed a little. “I’m actually quite a softy at heart,” he told me.

But some construction firms will feel that his original point was valid: if for some reason the bats decide to nest in a construction site this summer, you’ll have to wait until September when they start hibernating to be able to move them. Otherwise you’ll be breaking conservation laws.