When the ledges around yours get netted, the pigeons don't disappear — they relocate to the nearest unprotected alternative. If your neighbours have already netted, your ledge may already be on the birds' shortlist. Here's why acting before they settle in always costs less.

Pigeons on your HDB aircon ledge are silently damaging your outdoor unit and releasing dangerous pathogens into your home. Here's what causes the problem, what it costs to ignore it, and the only permanent solution.