Bonding, also referred to as adoption, was the establishment of an enduring psychic connection between a human and a Sphinxian treecat. It usually occurs moments after the treecat samples the human's mind-glow for the first time. Neither of the two parties can predict when a bond will form, or with whom. Indeed, the first human-treecat bond formed accidentally, before humans were even aware that treecats existed.
This first bonding occurred when Stephanie Harrington, an eleven-year-old girl, and Climbs Quickly, a male treecat, met. Stephanie had been trying to figure out who or what had been raiding small amounts of celery from farms and greenhouses across Sphinx. Her success in this regard caused her and the treecat to be in close proximity with each other, and the bond formed between them without either of them knowing exactly what had happened. It continued to develop for some time, especially during a fight they had with a hexapuma after she had a hang-gliding accident. Until her death, they remained inseparable. (HHA2.2: WPD)
On the instructions of Queen Adrienne whose life had been saved by a treecat, and who was herself a treecat adoptee, the Royal Manticoran Navy officially welcomed any treecat bonded to a crewmember aboard RMN vessels. In the Navy, as elsewhere, the nature of the relation between human and treecat was easily misunderstood, often as pet and owner, producing resentments. (HH1)
Nearly all treecats who bonded with humans were adult males. Some female treecats did so as well, but this was far less common. Most human adoptees were adult as well, but it was not unheard-of for children to be adopted. Indeed, Queen Elizabeth, Rachel Mayhew, and Honor Harrington herself were all adopted (by Ariel, Hipper, and Nimitz respectively) as children. Although such bonds involved considerable adjustments both for the young adoptee and his/her parents, they were considered highly beneficial for the child, in part because their 'cat helped them to develop a sense of empathy for others.
The loss of a bonded partner was difficult for either party. Since treecats had longer lifespans than pre-prolong humans, it was commonplace for them to outlive their partners. More than half the time, these "widowed" treecats committed suicide. Those who didn't generally returned to their clan. In very rare instances, the treecat would adopt another human, such as when Monroe adopted Justin Zyrr, or Samantha's adoption of Hamish Alexander. The latter case was also highly unusual in that Samantha adopted Alexander after having known him for a considerable time –- normally, bonding occurs within seconds after the first meeting between human and treecat. (HH10)