text: It really depends on the organism. Some have behavioral adaptations to avoid inbreeding, but in general one should assume that animals (except the ones with very large brains and social structures) don't have the capacity to recognize kin, certainly not as kin (i.e. they know this is their brother, parent, etc.). But they don't need to if, for example, they instinctively disperse at weaning, etc. However, you may want to consult this article by someone who's done a lot of work on this topic: http://www.bio.unc.edu/faculty/pfennig/lab/pfennig_files/kinrecoginization.htm