THE Pasir Ris-Punggol Town Council said the nuisance birds are swallows from Siberia and China, and that hundreds usually turn up in the evenings.

It has instructed its cleaners to clean the bird droppings more frequently.

The town council has also consulted the Agri-Food and Veterinary Authority of Singapore on the matter, and taken the following precautions:

• High-beam torch lights and laser beams were used to disturb the swallows to prevent them from returning to the blocks to roost 
• Netting was placed on other blocks to prevent the swallows from roosting

The town council has also consulted a bird expert and other organisations.

According to a TNP report last year, the birds usually arrive in September and fly off by March.