The question was investigated whether an insectivorous bird when hungry can form the concept of bilateral symmetry which might enable it to detect resting prey proficiently. Eight great tits of both sexes were trained in four experiments with insects as reward to discriminate either between a pair of figures that differed only in terms of the presence of bilateral symmetry (symmetric—asymmetric), or simultaneously between pairs of figures that were both symmetric (symmetric—symmetric) or not (symmetric—asymmetric). Symmetry concept formation was demonstrated in some of the Ss by a) generalization tests and b) a better performance with symmetric-asymmetric pairs as compared to symmetric—symmetric pairs. While one S attended to symmetry regardless of the orientation of the symmetry axis, another probably did not.