The biologist carefully lined up the measuring worms to compare their lengths.

Although it looks like a simple invertebrate, the acorn worm displays primitive chordate features such as a dorsal nerve cord and pharyngeal gill slits.

On warm summer nights, I used to watch the common glow-worm flashing softly among the grass.

On warm summer nights, common glow-worms light the hedgerows like tiny lanterns.

A sand tube worm anchored itself in the shifting sand and extended its feathery tentacles to catch drifting plankton.

After years of public health efforts, Guinea worm disease is now close to eradication in many affected countries.

During the expedition, the team photographed a giant tube worm extending its red plume above a hydrothermal vent.

The sand mason worm constructs a tube from sand particles and mucus, creating miniature castles on the tidal flats.

Coastal researchers found sand mason worms rebuilding their tubes after the storm.

After months of bullying, she finally snapped — even a worm will turn.