Kudus are very alert and nervous animals. They spend nearly all their time hidden in thick bush.They usually stand very still and are very difficult to spot. When disturbed in the bush habitat the animal will move away quietly or dash off after giving a loud, sharp alarm bark. They move surprisingly quietly through dense bush. As they run the bulls lay their horns back close to the shoulders so that they do not hit overhanging branches. As they run the bulls lay their horns back close to the shoulders so that they do not hit overhanging branches. The tail is curled up over the back exposing the white underside. This serves as an alarm signal and a marker for the rest of the herd to follow. Kudus are normally active in the early morning and late afternoon. In developed areas they become nocturnal to escape hunting. They live in small herds of up to about a dozen but large numbers can sometimes be seen at water holes. The composition of the herd changes during the year. They are not territorial animals. In the mating season males and females occur together. The rest of the time the sexes are separate. The females stay in their herds and the males live singly or in bachelor groups. Social grooming happens in all type of herds. Kudu usually mate between May and August. A bull checks the reproductive condition of females by sniffing of her urine. The bull follows her with his head stretched forward and his horns back. He stands behind her with his neck on the female rump. They mate only once for five to ten seconds. Cows leave the herd to give birth. A calf is usually born in tall grass. Its mother returns to her herd and visits the calf to suckle it three to five times a day. The calf stays hidden for one to two months. The get weaned at six months.