Weizmann physicists film weaver ants building nests with living zippers and weights

Physicists at the Weizmann Institute of Science described on 30 March 2026 how weaver ants, which live in the treetops of northern Australia and Southeast Asia, coordinate hundreds of workers to fold large leaves into a sealed nest. The study, by Professor Ofer Feinerman and staff scientist Dr. Ehud Fonio of the Department of Physics of Complex Systems with doctoral students Gadi Trocki and Michal Roitman, appeared in the journal Current Biology.

Weaver ant nests can contain from a hundred to several hundred leaves and house up to 50,000 ants. Because each ant is tiny compared with a leaf, the insects link their own bodies into temporary tools. Some form chains that span the gap between two leaves and pull them together like a zipper, starting at the base and working toward the tip. Others hang from leaf tips as living weights, using gravity to bend them down. Once the leaves are in place, workers glue them with silk produced by the colony's larvae.

To watch the process, the researchers collected colonies near Townsville in Queensland, Australia, and filmed them in the lab with an array of 52 synchronised 4K cameras as the ants built nests on a branch with four artificial leaves. By changing the starting tilt of the leaves, the team found a threshold: below it the leaves were bent downward, above it upward. In every case, the ants first joined one pair of leaves and then zipped the rest to that pair, so all leaves bent the same way and the nest closed into a sphere. Using tools from Gaussian geometry, the scientists showed that a closed sphere is the stable outcome of these simple local actions, giving the nest strength and internal space.

How the ants agree on a direction is still unknown; pheromone signals and group dynamics are among the explanations the team is testing.