Slime Attack

This creature's extraordinary goo could lead to recyclable bioplastics

- Elizabeth Anne Brown

Velvet worms like this one "sneeze" out a sticky goo with intriguing properties.

THE VELVET WORM, a squishy little predator that looks like the stretch-limo version of a caterpillar, has a whimsical MO: it administers death by Silly String.

In the leaf litter of tropical and temperate forests around the world, velvet worms stalk the night on dozens of stubby legs. The pocket-size predator-whose species range from less than half an inch to eight inches longcan barely see, so it bumbles around, hoping to literally bump into an edible bug such as a cricket or a woodlouse.

When it finds one, the velvet worm uses nozzles on either side of its face to shoot jets of sticky slime at its victim.

"It happens so fast it's almost like they're sneezing," says Matthew Harrington, a biochemist at McGill University who has studied velvet worms for a decade.

At first, the goo is a watery liquid, but in midair it transforms into jellylike ropes that ensnare the unlucky creature and stick it to the ground. As the prey struggles, the slime forms fibrous threads, and within seconds the substance hardens into a glasslike solid.