When you’re the size of a human, you worry about lions and tigers and bears. But if you’re a bacterium, a tiny nematode worm, just a millimetre long, can be a vicious predator. Nematodes are among the most common animals on the planet, and many of them hunt bacteria in soil and water. The microbes, in turn, have evolved many defences. Some secrete toxins. Others gather in large, invulnerable swarms*.

Now, a team of Chinese scientists have discovered the most outlandish strategy yet: some bacteria transform fungi into worm-killers.

Fungi aren’t known for their speed or mobility, but around 200 species have evolved ways of killing nematodes nonetheless. They use traps, including sticky nets and microscopic lassos made of single coiled