A species of spider that suckles its young

SUPERFICIALLY, INDIVIDUALS of a species of jumping spider called look like ants. This protects them from the attentions of spider wasps—a group of insects that catch and paralyse spiders in order to lay their eggs on the arachnids’ bodies, which thus act as a living larder for the wasps’ larvae. Ants are not, however, the only group of unrelated animals that resembles. They are also quite like mammals. That, at least, is the conclusion of a study just published in by Quan Ruichang of the Xishuangbanna Tropical Botanical Garden, in Yunnan, China.Female mammals produce milk to suckle their young. Before modern gene-based phylogeny developed, that was indeed the definition of a mammal. A few other types of animal do something similar. Pigeons, for example, generate a milklike secretion in their throats, which they feed to their squabs. But until now, only in mammals (or some of them, anyway) was lactation thought to be the basis of an extended relationship between parent and offspring. Dr Quan and his colleagues have changed that thinking.