Backswimmer Identification Guide
Learn to identify this pond insect that swims upside down using its oar-like hind legs.
Read the full Backswimmer encyclopedia entry →
Key Visual Features
Backswimmers get their name from their unusual habit of swimming belly-up, and this upside-down orientation is one of the easiest ways to identify them at a glance.
- Size: Typically 1 to 1.6 centimeters long, boat-shaped and compact.
- Body shape: Elongated, keeled, and convex on the back (which faces down while swimming upside-down), giving the body a rounded, boat-hull profile.
- Color: Often pale tan, cream, or light gray on the back (the side normally facing up when the insect swims inverted), with a darker brown or black underside — the reverse of typical countershading, which matches its upside-down lifestyle.
- Legs: Three pairs of legs, with the hind pair greatly elongated, flattened, and fringed with hairs, forming paddle-like oars used for powerful swimming strokes.
- Wings: Two pairs of wings folded flat over the back, giving a somewhat shield-like appearance from above; capable of flight to disperse between water bodies.
- Eyes: Large, prominent eyes that aid in detecting movement both above and below the water surface.
Where and When You'd See Them
Backswimmers live in still or slow-moving fresh water such as ponds, ditches, and the calmer edges of lakes, and are active from spring through fall in most temperate regions. They are most often seen resting just below the surface at a slight angle, periodically coming up to trap an air bubble against their body before diving again, and moving in quick, jerky bursts when swimming.
Similar-Looking Bugs
- Water boatmen: Very similar in overall shape and habitat, but water boatmen swim right-side up (not inverted) and have a flatter, more uniformly patterned back rather than the pale, convex back of a backswimmer.
- Water striders: Stay on top of the water's surface film rather than swimming within the water, and have a much more elongated, thin-legged body.
- Giant water bugs: Considerably larger and swim right-side up, with a broad, flattened oval body quite different from a backswimmer's narrow, keeled shape.
- Diving beetles: Have a hardened, domed shell-like back (elytra) typical of beetles, rather than the flatter, membranous wing covers of a backswimmer.
Quick ID Checklist
- Swims upside-down (belly-up) — the single most reliable field mark
- Boat-shaped, keeled body about 1–1.6 cm long
- Pale back with a darker underside (reversed countershading)
- Long, flattened, oar-like hind legs fringed with hairs
- Found in still or slow-moving fresh water, resting just below the surface
Frequently asked questions
What is the easiest way to identify a backswimmer?
Its swimming orientation: a backswimmer swims upside-down (belly facing up), which is the clearest and most reliable field mark to distinguish it from similar water insects.
How is a backswimmer different from a water boatman?
Water boatmen swim right-side up and have a flatter, more evenly patterned back, while backswimmers swim inverted and have a paler, more convex back.
Why does a backswimmer have pale coloring on its back?
Because it swims upside-down, its normally 'under' surface faces up, so its coloring is reversed from typical countershading, appearing pale on top and darker below.
Can backswimmers fly?
Yes, most backswimmers have two pairs of functional wings and can fly to disperse between ponds and other bodies of water.
Backswimmer identified by the community
Recent Backswimmer finds identified with Bug Identifier.
