Andy Sands / Leaf-cutter bee (Megachile ligniseca) female carrying dead leaf section back to plug the end of bamboo tube in garden bee hotel, Hertfordshire, England, UK, July

Pete Oxford / Apatani woman woman with facial tattoos and traditional cane nose plugs / Yapin Hulo made to make them look unattractive to males from other tribes. These facial modifications are now outlawed. Apatan...

Will Watson / Female Great diving beetle (Dytiscus circumflexus) view of underside with cloacal sperm plug from previous mating, UK, captive.

Tui De Roy / Eroded basaltic lava plug, at Buccaneer Cove, James Island, Galapagos Islands, Ecuador, March 2013.

Tui De Roy / Eroded basaltic lava plug, at Buccaneer Cove, James Island, Galapagos Islands, Ecuador, March 2013.

Tui De Roy / Eroded basaltic lava plug, at Buccaneer Cove, James Island, Galapagos Islands, Ecuador, March 2013.

Laurent Geslin / Person switching off electric switch at wall socket.

Pat Tuson / Close up of a recharger plug for electric car, London UK

Alex Hyde / Male house spider (Tegenaria sp) male next to plug hole, Derbyshire, UK, September.

Ernie Janes / Silhouette of House spider (Tegenaria domestica) on bath plug, UK

Philippe Clement / European common house spider (Tegenaria atrica) in washbasin / sink next to plug-hole, Belgium

Philippe Clement / European common house spider (Tegenaria atrica) in kitchen sink next to plug-hole, Belgium