How to Get Rid of Shore Flies?

What Are Those Tiny Flies Near Standing Water in the Bathroom?

The tiny flies hovering near standing water in your bathroom are very likely shore flies (family Ephydridae) — small flying insects that thrive in damp environments. They measure only 2-5mm, even smaller than drain flies, and often skate rapidly across water surfaces, sometimes mistaken for tiny spiders.

What Do Shore Flies Look Like?

• Very small body, just 2-5mm long — about half the size of a drain fly
• Slender body, grayish-black or dark brown in color
• Relatively long legs that let them move and skate quickly on water surfaces or damp areas
• Often seen crawling or skating on thin water films, moving with agility
• Weak fliers; usually only make short, low flights within damp areas

Shore Flies vs. Drain Flies

• Shore fly: Smaller and more slender, long legs, skates on water surfaces — moves like a tiny spider
• Drain fly: Short, plump, hairy body with wide oval wings; usually sits motionless on walls

Where Do Shore Flies Appear?

• Standing water on bathroom floors — around shower drain areas, under sink plumbing
• Plant saucers with long-standing water
• Around floor drain edges that stay damp or hold water
• Around the kitchen sink, especially near the drain opening
• Balcony areas where rainwater collects, under A/C drain pipes
• Any corner with persistent dampness and standing water

Why Do Shore Flies Appear?

Shore flies signal that your home has standing water that has been sitting for more than 3-5 days or humidity that is consistently very high. Their larvae live in water. As long as standing water remains, they can complete their entire life cycle from egg to adult. The flies themselves don't bite and don't spread disease, but their presence is a clear signal — you have a standing water problem that needs attention.

How to Get Rid of Shore Flies

• Remove all visible standing water; mop floors dry and keep them that way
• Clean floor drains regularly; pour a kettle of hot water (60 degrees C / 140 degrees F or hotter) down each drain at least once a week
• After using the bathroom, open a window or run the exhaust fan to ventilate and reduce humidity
• Empty plant saucer water promptly; don't let water sit for more than 2 days
• Check pipes for leaks and repair any you find
• After 1-2 weeks of following these steps, shore flies will disappear on their own — no insecticide needed