Movement and migration are fundamental parts of the life cycle of most organisms on Earth and occur at an astonishing range of spatial and temporal scales, from iconic pole-to-pole migrations of some birds to diel migrations of enormous amounts of millimeter-sized crustaceans through the waters of oceans and lakes. To move or not to move in a certain situation is a decision that is often taken by individuals, suggesting that not all may take the same decision, which in turn means that partial migration is a common phenomenon. Moreover, moving and migrating require energy and although some organisms are specialists in, for example, running, swimming, or flying very fast or for a long time, others are more generalists, saving their energy for other activities. In an evolutionary perspective, those different choices have led to a tremendous diversity in ways of moving and in migratory patterns, including trans-generational migrations among some insects, “hitch-hiking” by small organisms, such as parasites, leading to the spread of many diseases, and non-stop flights by some birds over oceans without the possibility of eating or resting. Although many migratory routes and patterns are constant over time, environmental change, such as climate warming, may strongly affect how organisms, including humans, move and migrate in the future.