Are you dealing with Cluster Flies in spring? here’s how to stop them with key points on preventing them entering your home and clearing them out once they have invaded!
Unlike other flies, cluster flies spend the winter months hibernating inside lofts, wall cavities, and other quiet areas. As the weather warms up in spring, they become active again and try to find their way back outside.
This is why you may notice them gathering around windows or moving slowly inside your property. They are not breeding indoors, but their presence can still be frustrating and difficult to manage.

Signs of a Cluster Fly Problem in Spring
Think you might have cluster flies on your property? Look out for these common signs:
- Flies gathering around windows or light sources
- Slow-moving flies appearing on warmer days
- Dead flies on windowsills or in loft spaces
- Flies reappearing even after being removed
- Increased activity in unused rooms or loft areas
How to Prevent a Cluster Fly Problem
Stopping cluster flies early can help reduce the issue:
- Seal entry points – Check for gaps around windows, doors, and rooflines
- Keep lofts and unused areas maintained – Reduce access to sheltered spaces
- Install window screens – Help prevent flies entering or re-entering
- Repair cracks in walls and external areas
- Keep windows closed where possible during peak activity
Don’t Wait for a Cluster Fly Problem to Get Worse
Cluster flies can be persistent, especially if they have already settled inside your property over winter. The longer the issue is left, the more noticeable it can become.
Whether you’re already seeing signs of cluster flies or want to prevent further activity, it’s best to act early. At All Pests, we offer professional, discreet, and effective pest control services to help you stay protected throughout the year.
