A scorching summer evening and people gather at roadside restaurants, order spicy crayfish and bottles of ice-cold beer, enjoying their meal and a good time with friends. Delicious crayfish is a popular dish in China, as it is in many countries, but people may not realize that it is actually an invasive alien species that can threaten aquatic animals and plants.

Some have proposed that the crayfish should be treated as a food resource, and that the population should be controlled through continuous and profitable harvesting. But ensuring their captivity can prove difficult. When they break the confines of their captivity, their inevitable spread can trigger wider problems.

The story is recounted in Invasive Alien Species, a recently published science book written by scholar and author Ran Hao. Ran is adept at writing books that popularize science and has won Wenjin Book Award, one of China's top prizes, twice for his two books Fantastic Ants: Wonder of Evolution and Animal Groups.

According to Ran, in recent years, the phenomenon of invasive alien species has attracted greater attention, since it is increasingly difficult to ignore. He started to pay attention to the phenomenon when he was a student, and published an article focusing on the issue online in 2004. He hoped to find a book that elaborated on the issue, but wasn't able to find one that satisfied his curiosity. As a result, he decided to write one himself.