Spiders (order Araneae) are air-breathing arthropods that have eight legs and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other orders of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every habitat with the exceptions of air and sea colonization.
Musth or must is a periodic condition in bull (male) elephants, characterized by highly aggressive behavior and accompanied by a large rise in reproductive hormones. Testosterone levels in an elephant in musth can be as much as 60 times greater than in the same elephant at other times. However, whether this hormonal surge is the sole cause of musth, or merely a contributing factor, isunknown. Scientific investigation of musth is problematic because even the most placid elephants become highly violent toward humans and other elephants during musth.
Impala calves are suckled for four to six months; young males—forced out of the all-female groups—join bachelor herds, while females may stay back.
