Wootbox Animals - Subscription Box - (Wootbox June 2020)
Animals (also referred to as metazoa) are multicellular eukaryotic organisms that form the biological kingdom Animalia. With few exceptions, animals consume organic material , breathe oxygen , are able to move , can reproduce sexually , and grow from a hollow sphere of cells, the blastula , during embryonic development . Over 1.5 million living animal species have been described —of which around 1 million are insects —but it has been estimated there are over 7 million animal species in total. Animals range in length from 8.5 millionths of a metre to 33.6 metres (110 ft). They have complex interactions with each other and their environments, forming intricate food webs . The kingdom Animalia includes humans , but in colloquial use, the term animal often refers only to non-human animals. The scientific study of animals is known as zoology . Most living animal species are in the Bilateria , a clade whose members have a bilaterally symmetric body plan. The Bilateria include t...