Small Flies, Big Problems


One of the most frustrating pest issues for restaurants is fruit and drain flies.  They’re small, but once these annoying little buggers get established inside a restaurant, they become extremely difficult to get rid of.

Most restaurant owners keep a clean facility and that’s what is so frustrating. How can there be so many annoying flies when their staff keeps every area spotless?

Because sanitation isn’t everything.

In some cases, cleaning practices can even add to the issue.  Every restaurant has weak or critical points –  areas that create an environment ideal for flies.  Find your weak points and then put together a program that achieves long-term control and elimination.

The first step is easy, where are you finding the flies?  Fruit and drain flies are weak fliers and have a very short range from their breeding site.  The average distance is about 10-15 feet from the breeding site.  This will help you find potential areas easily.  If you’re finding flies by the bar, chances are that there is something by the bar, or within 10-15 of the bar that is causing the issues – not the dumpster in the back of the parking lot.

The four most overlooked areas:

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Moisture – Anything that allows moisture to sit and mix with organic matter 24/7 is key.  Look for leaks under sinks and equipment.  Some areas that are often overlooked are things that touch and rest on the floor.  This allows areas to stay wet.  Look for hoses or pipes that rest on the floor or milk crates that aren’t moved regularly.   Look beneath these items, and you may find a wet, gunky mess that you never knew existed.  One of the most common and overlooked moisture areas in restaurants is missing grout and broken tiles.  These are ideal breeding sites for flies.  A little grout may be all you need to eliminate a long established issue.
Drains – Most restaurants check their beer and soda drainage lines as well as hosing down their floor each night.  But the floor drains are often overlooked and can catch large debris and trap huge amounts of organic matter that rots away.  Drain covers and filters should be run through the dish washer on a regular basis to remove organic matter, and using a Bio Enzymatic Cleaner in drains is great to remove the bacteria that attract flies.
Vegetables – Many people just assume the flies are brought in with fruit.  But they are more likely to come into your restaurant in rotten vegetables, especially potatoes and onions.  Just one rotten piece in a bag can have thousands of fly larvae.  It’s not just new deliveries, but loose and rotting pieces under your storage area can cause an ongoing cycle.
Missed Sanitation Areas – Your floor is spotless, the stainless steel equipment is sanitized and yet flies are still breeding.  You need to go further. Pull out refrigerators and equipment.  What does it look like behind and under these areas?  One bottle cap or one mixing straw can create hundreds of flies.  Another missed spot is equipment motors.  We’ve discovered stagnant water, lemon wedges and leftover food:  a perfect environment for breeding flies.

When we inspect restaurants, we find them clean and organized with 99% of the areas properly cleaned.  But pests are going to find the 1% that’s overlooked.  These are the areas that need to be addressed if you want your facility to be pest free.


Michael Broder is the President of BHB Pest Elimination.  Since 1969, BHB Pest Elimination has been dedicated to the food and hospitality industry.  If you need help in identifying your Weak and Critical areas, or for any information on our Pest Elimination Programs, we will gladly provide you with a free on site evaluation.   212-242-3383 or

Dr. Joel R. Grassi is an Accounts Manager at BHB Pest Elimination. He is certified Bed Bug Specialist and a NYS licensed applicator. If you would like him to provide you with a complimentary assessment of your restaurant as it relates to pest management, please contact him at 212-242-3383 or