A thriving beaver population is threatening the stability of the Netherlands’ sea defences. The Mammal Society has brought together other wildlife groups to work out how to protect these important water-blocking dykes from the small but potentially destructive semi-aquatic rodents. Beavers play an important ecological role in the Netherlands and were initially brought in to increase biodiversity. The beaver-breeding program began in 1988, and since then the beaver population has grown exponentially. There are now an estimated 700 beavers residing in the country’s streams and canals. Triumphant mating habits combined with the beavers’ ability to breed so successfully in the Dutch countryside mean they have been moving beyond the southern province of Limburg and entering towns and cities that may not be prepared for the influx. With the Dutch beaver population expected to hit around 7,000 by 2032, the need to take pre-emptive action is now a very important theme.