Gathering in large numbers is usually a good way of protection yourself against predators, and it’s no surprise that mass defence is a common strategy in the natural world. But it doesn’t always work. There is one hunter that has found a way to use group defence to its advantage. It allows its prey to gather in large numbers and then freezes them in place with a chemical weapon, providing it with a bountiful banquet to eat at its leisure. It’s called Dictyostelium caveatum.

The majority of dictyostelids, such as D.discoideum, are some of nature’s most vivid examples of cooperation. They live most of their lives as single cells that eat bacteria, but a lack of food drives them to