1.Population Density and Food Quality (2)Not all species,however,have these traits. Some species do not migrate at all,even if population density and/or feeding needs would induce them to do so. (3)In spite of the fact that bad environment conditions can induce migration in migratory insects,there are,for unknown reasons,some insect individuals who migrate but do migrate to a further place even there is enough food near by.(2) Not all species, however, have these traits. Some species do not migrate at all, even if population density and/or feeding needs would induce them to do so. (3) In spite of the fact that bad environment conditions can induce migration in migratory insects, there are, for unknown reasons, some insect individuals who migrate but do migrate to a further place even there is enough food near by. 1. Population Density and Food Quality Population Density and Food Quality