During breastfeeding, the Przewalski mare (Equus ferus przewalskii) progressively becomes aggressive towards her foal to prepare it for weaning. This controlled behavior of maternal aggression begins as early as 2 to 3 weeks after birth with an attack every ten feedings or so and develops during the 2nd and 3rd months when the foal becomes less delicate. The mare may then strike the ground, whip her tail, or push the foal away with a kick or bite, yet without injuring it.