Could birth control milkshakes solve California’s rat problem?

If left to their own devices, a male and female rat can produce up to 15,000 babies in a single year. It’s an incredible statistic that underscores the difficulty rats have posed among human populations for centuries. A study out of Columbia University found that the average subway rat carried 18 viruses previously unknown to science. Throughout history, rats have caused more human death than any other animal on earth.

As California City News reported previously, the COVID-19 pandemic has exacerbated the rat problem. During lockdowns, rats that traditionally found food sources in restaurant dumpsters had to seek food elsewhere. That drove them further into housing developments, residential areas and the suburbs. 

Thankfully, one California city may have found a solution. Alongside more traditional measures, San Francisco’s Recreation and Park Department is deploying a rodent contraceptive called ContraPest around its public parks. It’s described as a “rat milkshake” full of fat and sugar — and a substance that renders the rodent drinker infertile.

ContraPest does not contain any poisons or noxious agents. It accomplishes the goal of population control without firing a single shot. That eliminates the risk of harm to other animals higher up in the food chain. Further studies are needed but, anecdotally, ContraPest appears to be very effective. 

ContraPest could be the future of municipal rodent management. That’s quite incredible when you consider that the elixir was created by accident. It’s the invention of a wife and wife team of scientists, one of whom entered the scientific field in her mid-40s after a successful career in real estate development. 

Read more about the future of rat contraception here.