The most dangerous aspect of excessive rodent populations is that they or their parasites can transmit deadly diseases and infections to humans. These include multi-resistant germs, hantavirus, the plague (e.g., Madagascar), SARS, leptospirosis, which in its most severe form can cause liver and kidney failure, as well as Lyme disease and TBE (tick-borne encephalitis), which can cause meningitis. Researchers have now found rats that are positive for coronavirus.

Pests destroy up to 25% of global crops, food, and feed supplies every year. They transmit serious diseases and epidemics (including swine fever, foot-and-mouth disease, and bird flu). This puts livestock at maximum risk. At the same time, farmers have great difficulty keeping rats and mice out of their barns. Rats in particular spread these diseases from one farm to another as they migrate.
Pests such as rats and mice also gnaw through wood, plastic, and insulation material; even concrete is no significant barrier for them. They thus cause massive damage to building structures. This jeopardizes the integrity and safety of houses and industrial facilities.

These harmful rodents reproduce rapidly. For example, each female rat can give birth to 4-12 young 4-7 times a year, i.e. a maximum of 84 per year (up to 2,000 offspring per female rat). In New York alone, there are currently an estimated 15 million rats, in Berlin around 3-6 million, and in Germany as a whole, the figure is estimated to be around 300 million. Worldwide, there are an estimated 10 billion animals, and the trend is rising. Mice reproduce even more rapidly. Their number in our country is currently estimated at 3.5 billion.

Another obstacle to control is increasing resistance. Estimates suggest that, on average, 40-70% of rat strains in Western countries are already resistant to first-generation rodenticides. Resistance to second-generation rat poisons is growing steadily.
The key problem with second-generation rodenticides is their extremely high environmental toxicity and secondary and cross-toxicity. The substances are difficult to break down and, when they do, it is a very slow process. They accumulate heavily in the soil and waterways. As they cannot even be broken down in sewage treatment plants, they have already found their way into our drinking water. Several studies by the German Federal Environment Agency (UBA) have shown that all bodies of water in Germany are already contaminated with rodenticides. Of the animal species studied, for example, 99% of fish, 70% of birds of prey, and 60% of foxes are contaminated with rat poison.​

Animals other than those targeted for control also die in large numbers when they accidentally eat the bait containing current rodenticides or the poisoned rodents. Animals endangered by this include protected species such as birds of prey and scavengers, but pets (dogs, cats) and foxes are also at risk.

Second-generation rodenticides have already been completely banned in several countries due to their toxicity and persistence. In the remaining European countries, including Germany, these rodenticides may only be used by trained specialists and under strict conditions. From July 1, 2026, permanent baiting in food retail outlets will be completely banned, regardless of infestation. This poses an immense challenge for the entire industry.
Technical solutions, such as snap traps, automatic firing devices, and drop weights, can only be used to a limited extent. In addition, rats quickly recognize them as traps and subsequently avoid them (so-called behavioral resistance). Mice also exhibit avoidance behavior. These control methods are therefore unsuitable for destroying entire populations or preventing the (re)colonization of infestation-free areas.