Milk comes from mammals. It is a kind of clearly mammal. Even our government knows it. And yet, Chinese scientists have documented jump spiders that provide their offspring with drops of a liquid rich in nutrients from a furrow in the mother's body. It is the exclusive food for thorns until it begins to look, and even they still take it until they reach something more mature. The results are recorded in Science.
Cockles and pigeons also provide their offspring with a qualified "milk" substance, because it comes from the body and provides the only source of support for young people. The mums of the rooster place this substance in the chicken sack where their embryos develop.
Parents-mothers-generate milk from culture and feed it to children's birds during the first days of life, until infants can digest real foods. The cultured milk consists of cells full of nutrients that are scattered in flakes from the inside of the primary bird crops, which are under the neck.
Toxeus magnus They are the jumping spiders studied here, and they look like ants. Your childcare method also seems to be different from the two previous examples. They have a specialized organ that makes the milk, suggested by the researchers, made of unfeasible eggs that are converted into food for surviving children.
These spiders also live in small and nuclear nests, where the mother occupies the children even after maturity. For a while, young people rush into forage, but continue to go home, making them even more similar to mammals.
Therefore, this definitely is not lactating, but these researchers believe that "it is compared functionally and behaviorally with breastfeeding." It also serves a similar evolutionary need: compensate for uncertain access to food and keep young people in the nest for as long as possible to protect them from predators.
Saltadora spider milk has a protein content of 123.9 mg / ml, four times higher than cow's milk. Vegan is not.
Science, 2018. DOI: 10.1126 / science.aat3692 (About DOIs).