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Pond and stream · Beetles
Whirligig beetle
Gyrinus substriatus
Tiny, oval, shiny black beetles that spin round and round on the surface of the water like dodgems.
- Size
- About 6mm long
- Look for them
- April to October
- Where
- The surface of ponds, canals and slow streams, in groups
My spotter's list
Whirl after you in a spinning group. Move your pointer and see.
When to look
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Whirligig beetles
Good to know
Six things about whirligig beetles
EyesFour eyes
Each eye is split in two. The top half watches the air and the bottom half looks down into the water.
SpinWhy they spin
The whirling makes it hard for a fish or a bird to pick out one beetle.
RadarRipples like radar
Its antennae rest on the surface and feel the ripples bouncing back, so it never bumps into its neighbours.
LegsLegs like paddles
The back two pairs of legs are flat paddles that beat about fifty times a second.
DiveA bubble to breathe
When alarmed it dives, carrying a bubble of air on the tip of its tail.
SmellA smelly defence
It gives off a milky liquid that makes fish spit it out.
The real thing
Photos of whirligig beetles
Photos are from Wikimedia Commons, used under the free licences shown. They have been resized, and cropped where they appear in link previews.
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Out and aboutHow to spot them
Look for a patch of shining specks circling on calm water near the bank, often in the shade of an overhanging branch.
Lend a handHow to help
They need open water, so keep part of a pond clear of duckweed and lily leaves.
Following youLadybird
Who should follow you?
These live somewhere else: choosing one takes you to their page.
The garden
These live somewhere else: choosing one takes you to their page.
Meadow and hedgerow
Pond and stream
These live somewhere else: choosing one takes you to their page.
The log pile
These live somewhere else: choosing one takes you to their page.
After dark
Bugs from other parts of the world live on their own pages: choose another.
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