Why Flies Increase After Rain and in Humid Weather

Many people notice a surge of flies after the first rains. It is not your imagination.

The short answer

Warmth and moisture speed up fly breeding and make waste, drains and compost break down faster, giving more breeding material. Rain also flushes flies indoors. Prepare by clearing standing water and garbage, cleaning drains, covering bins, fixing leaks, keeping compost covered and installing screens. If flies persist, look for a nearby breeding source or call a professional.

Why it happens

• Heat and humidity speed up life cycles.
• Wet waste rots faster and attracts flies.
• Overflowing drains and puddles provide breeding sites.
• Rain pushes flies indoors.

What to do

1. Clear waste promptly.
2. Clean and cover drains.
3. Keep compost and bins covered.
4. Fix leaks and avoid puddles.
5. Use fly screens and seal gaps.

Monitor

• Check bins, drains and corners often.
• Look for maggots, which show a breeding site.

When to call a professional

If the problem is widespread, keeps returning or you are unsure what you are dealing with, a professional inspection will save time and avoid wasted effort.

Frequently asked questions

Is the increase seasonal?

Often, yes.

Can I stop it?

You can reduce it with sanitation.

Do sprays help?

Only short-term.

Should I wait for rain to end?

No. Fix sources early.

This guide is part of IPest's complete resource on fly control. For identification help, prevention and treatment options, see our full fly control guide for Bangalore.