Dutch water boards capture 84,438 muskrats in 2025 as invasive rodents threaten dikes

Muskrats, semi-aquatic rodents that dig extensive burrows in riverbanks and dikes, surged across the Netherlands in 2025. The Association of Dutch Water Authorities reports that the invasive species are threatening the country’s flood defenses by weakening dikes and embankments through their tunneling.

The 21 Dutch water boards captured 84,438 muskrats last year, more than 28 percent higher than in 2024. The rise was concentrated in western provinces, where Hoogheemraadschap van Schieland en de Krimpenerwaard, Hoogheemraadschap Rijnland, and Waterschap Amstel, Gooi en Vecht accounted for over half of the captures, deploying additional personnel to control the growing population.

Vincent Lokin, a board member of the Association of Dutch Water Authorities, highlighted the stakes. “About 17,000 kilometers of dikes, regional embankments, and other water defenses protect the Netherlands from floods,” he said in a press release. “The pressure on our dikes and embankments will only grow due to more extreme weather. Preventing burrowing by muskrats and beaver rats remains a crucial task for the more than 400 specialized rat control officers of the 21 water boards.”

Each muskrat can move the equivalent of thirteen wheelbarrows of soil a year, weakening dikes, blocking waterways, and harming vegetation.

Muskrats swim into the Netherlands from Germany via rivers and streams. Most are trapped near the border, preventing them from establishing new colonies inland. Highly fertile, a single pair can produce thousands of offspring in a few years.

Beaver rat captures reportedly remained about the same in 2025 at 1,831 trapped. The rats were mostly caught along the eastern border. Populations in the area remain high due to Germany's mild winters. The Netherlands has had no resident beaver rat population since 2013, and border trapping reportedly prevents their spread nationwide.

Water boards rely on drones and DNA analysis of water to track and manage these invasive species. The Association of Dutch Water Authorities aims to eliminate muskrats in the country by 2034. “The rat control teams increasingly collaborate across regions, contributing to the shared goal of having no muskrat population in the Netherlands by 2034,” Lokin said.