The silent invasion of alien species is causing significant financial losses for Europe. According to recent research published in Nature Ecology & Evolution, the economic damage caused by animals and plants introduced into previously uninhabited environments has been severely underestimated. From 1960 to 2022, the European continent suffered losses exceeding $1.584 trillion, 71% of the global total. This is the largest total ever recorded, with the United Kingdom topping the list of the most impacted countries. The study, co-authored by experts from the University of South Bohemia and McGill University, gathered data from 197 countries, including many previously excluded from official estimates. Alien species, which are frequently introduced involuntarily through trade or transportation, can sometimes integrate without causing harm. However, in other cases, they proliferate uncontrollably, resulting in significant costs for agriculture, fishing, forests, and infrastructure, as well as a threat to biodiversity. In Italy, the most notorious examples are the Louisiana red crayfish and the blue crab, the latter now considered the most invasive species in the country. To deal with its spread, the government has allocated over €55 million. The global cost of invasive plants is close to $926 billion. Next in number are arthropods (insects, arachnids, crustaceans), with 830 billion, and mammals, with over 260 billion. Wild boars, increasingly common in Italy, cause damages estimated at over $121,000 per square kilometer.