"Simberloff and Ricciardi have captured Elton's thinking on biological invasions over the subsequent 25 years. This proves not only to be an informative read but also a wonderful insight into the mind of one of the 20th century's leading ecologists. ... We are lucky to have this new edition that loses none of the magic of the original but hopefully will encourage a new generation of ecologist to read this classic work." (Philip Hulme, The Niche, 2020)