Про крокодилов из Википедии:
Цитата:
"Reproduction and maturity
Once the eggs are laid, the expectant mother covers the eggs with sand, and then guards them for the 3 month incubation period. The father-to-be will often stay nearby, and both parents will fiercely attack anything that approaches their eggs. The impending mother will only leave the nest if she needs to cool off (thermoregulation), by taking a quick dip or seeking out a patch of shade. Despite the attentive care of both parents, the nests are often raided by humans, monitor lizards, and other animals while the mother is temporarily absent.
The hatchlings start to make a high-pitched chirping noise before hatching, which is the signal for the mother to rip open the nest. Both the mother and father may pick up the eggs in their mouths, and roll them between their tongue and the upper palate of their mouth to help crack the shell, and release their offspring. Once they are hatched, the female may lead the hatchlings to water, or even carry them there, in her mouth.
The new mother will protect her offspring for up to two years, and if there are multiple nests in the same area, the mothers may form a crèche (ясли-сад). During this time, the mothers may pick up their offspring to protect them, either in their mouth or in her gular or throat pouch."
Надо же, а, какие милые создания эти крокодилы, оказывается.
И самцы и самки охраняют свои гнёзда в течение 3-х месяцев, да ещё и ясли-сады устраивают, когда народу много.
А ещё, оказывается, крокодилы самые голосистые из всех рептилий.
Вот здесь звуки вылупившихся крокодилят есть.
http://www.flmnh.ufl.edu/cnhc/croccomm.htmlНасчёт
материнского инстинкта у животных: всё дело в гормоне
окситоцине, похоже?
Цитата:
Bonding. In the Prairie Vole, oxytocin released into the brain of the female during sexual activity is important for forming a monogamous pair bond with her sexual partner. Vasopressin appears to have a similar effect in males [1]. In people, plasma concentrations of oxytocin have been reported to be higher amongst people who claim to be falling in love. Oxytocin has a role in social behaviors in many species, and so it seems likely that it has similar roles in humans. It has been suggested that deficiencies in oxytocin pathways in the brain might be a feature of autism.
Maternal behavior. Sheep and rat females given oxytocin antagonists after giving birth do not exhibit typical maternal behavior. By contrast, virgin sheep females show maternal behavior towards foreign lambs upon cerebrospinal fluid infusion of oxytocin, which they would not do otherwise
А ещё могут кошки выкармливать щенят (или кто там, свиньи?), и медведь медвежонка может усыновить (помню читал какую-то книгу, "Гризли" что ли 
Я вообще-то не внимательно смотрел, только эпизод как крокодилиха переносит детей. Я думал, что она просто запоминает место своего гнезда. Скорее всего у разных видов крокодилов по-разному.
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