A mysterious pulsating hum has been keeping people in the British town of Hythe awake at night, and scientists say there’s definitely something fishy about it.

Residents have complained to the local council, saying they’ve had to leave the area just to sleep. Some people have even gone to the doctor, suspecting they had tinnitus.

Blame has been placed on everything from industrial noise to passing cargo ships, but the Scottish Association for Marine Science thinks it’s found the answer: male midshipman fish.

The nocturnal fish emit a deep, resonating drone that attracts females, and once the creatures get started, they can hum all night long.

The strange mating ritual creates a sound of such low frequency and long wavelengths that it carries through the ground and into homes.

This isn’t the first time midshipman fish have interfered with people’s sleep. Last year the mysterious sound was so loud that it woke Seattle residents in the middle of the night.

Listen to the midshipman's hum in the video below.

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