A gecko holds on with physics, not glue

A gecko can hang from a pane of glass by one toe — and there isn't a drop of glue involved.

Look closely at the underside of those feet and you'll see ridges, like fingerprints. Each ridge is covered in millions of microscopic hairs called setae, and each seta splits again into hundreds of even finer tips. That branching gets the gecko's foot so intimately close to a surface that the faint attraction between molecules — van der Waals forces — adds up to a grip that carries the whole animal.

It's dry, reusable and instantly switchable. The gecko peels its toes off by changing the angle, which is why they walk with that odd, deliberate curl of the foot. The discovery sent engineers chasing gecko-inspired adhesives for robots and climbing gear.

Why it matters at home: that grip depends on clean, intact skin. Dust, residue and stuck shed around the toes blunt it, and a crested gecko that suddenly slides down the glass is telling you something. Watch the feet during a shed — retained skin on toes can tighten and cost a gecko a digit.

Sticky feet are also a reminder that your lid must be secure. Smooth walls are not a barrier.

If toes look swollen, dark or ringed with old skin, see a vet experienced with reptiles rather than pulling at it. 🦎