Corals and reef fish choose nice homes Young animals tend to disperse into new habitats. Can we use populations in protected areas to colonize nearby recovering or overused habitats? It seems that for corals and reef fish, the answer may be no. Dixson et al. show that dispersing juvenile corals and reef fish were overwhelmingly attracted to healthy reefs but were repelled by seaweeds that colonize degraded reefs (see the Perspective by Bruno). Thus, even species that appear passive in their choice of habitat may have stronger preferences than we thought. Science , this issue p. 892 ; see also p. 879