Summary.1Parent Coot treat all young conspicuously unlike their own as territorial intruders.2Parents with young less than two weeks old will tolerate, feed and brood young similar in appearance to their own. Three cases of permanent adoption are recorded.3Parents with young much over a fortnight old will not tolerate any strange chicks, however similar. This appears to prove that they recognize their own young individually.4The reactions of the young are controlled by releasers. Two are cited, viz. releasers of the following, and alarm, reactions.5Chicks up to at least eight hours old will follow men, accept food from (hem, and respond to calls made by them.6This tameness disappears by the second day (except in the case of hand‐reared young). Imprinting is by then complete.7At first young will follow and beg from any adult Coot.8At 8–11 days young learn to avoid adults in an attitude of attack.9Individual recognition of adults develops at about three we