Increased international trade and human movement, particularly since the Industrial Revolution, have resulted in the accidental movement of species worldwide at an unprecedented scale. Even though it has been recognized for a long time that humans introduce invasive species, invasion biologists have mostly focussed on the role of factors directly linked to the biology of organisms rather than human-mediated dispersal. Understanding how globalization affects the accidental transport of invasive species is urgent, because biological theory alone cannot explain current invasions, or predict those likely to happen in the future. In this presentation, I will focus on temporal dynamics, complex introduction histories and global species flows of invasive insects. In addition to understanding the global dispersal of insects, it is important to explore to what extent invasive species can establish under environmental conditions that are different from those encountered in their native range. In this context, I will present some of our recent work on climatic niche shifts in ants and discuss potential mechanisms underlying these niche shifts.