What caused this? Over 10 dead bats found scattered around Lentor Avenue

Stomper Mitch came across the carcasses of more than 10 bats in Lentor Avenue this morning (Jun 2).

He wonders what could be the cause of the deaths.

Said the Stomper:

"I found bats' dead bodies scattered on the grass, pavement and road on Lentor Avenue this morning, 2 June.

"In total, there were more than 10 of them. I posted a few photos here. It looks like they have been dead for a day or two.

"What could be the cause of this? Pesticide or some other reason?"