An apparatus (10) for determining the viability of an egg, which apparatus (10) comprises shielding means (12, 14), emitting means (30) and detecting means (32), the arrangement being such that, in use, the shielding means (12, 14) inhibits exposure of an egg to background infra-red radiation, said emitting means (30) can emit electromagnetic radiation at infra-red wavelength(s) to impinge on the egg, and the detecting means (32) are positioned to detect at least a part of said electromagnetic radiation that has passed through the egg, the apparatus further comprising means for processing an output signal of the detecting means to determine whether there is a cyclical variation in the intensity of the infra-red radiation leaving the egg corresponding to action of a heart, the existence of said cyclical variation indicating that the egg is viable.