There are two hormonal issues which help to ensure that the bond between mother cat and her kittens is strong and that the kittens are trusting during their first few weeks after birth.
Firstly, the nursing mother receives a wave of the hormone oxytocin which is produced in the hypothalamus and is secreted into the bloodstream by the posterior pituitary gland (located near the center and bottom of the brain). This drives her to prioritise her kittens. Oxytocin, as you have probably heard, is a hormone that plays a role in social bonding and reproduction, and also during the period after childbirth, in humans. It is called the ‘love drug’ as it is associated with empathy, trust, relationship-building and sexual activity. In humans, the level of oxytocin increases during a sexual orgasm and a hug.
From the kittens’ perspective, it is a lack of stress hormones, such as adrenaline, which helps to ensure a trusting relationship between them and their mother. Kittens have an early inability to produce stress hormones. Accidents can happen when they are feeding. For example, if a kitten suckles for too long and the mother decides to leave the nest, the kitten can be dragged out which would be a traumatic experience.
Indeed, it might be the most traumatic experience that a very young kitten suffers. There’s a potential for harm. Without the stress hormones kittens are unlikely to make an association between their mother’s scent and the shock of falling out of the nest to the ground. Incidents like this have no lasting impression on the young kitten’s brain.
If kittens had the stress hormone they might shy away from their mother when she returned as opposed to immediately reattaching themselves to her breast for feeding.
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