As usual, the infographic says all I want to say on this. It is all about merging feline scent to make each cat feel at home (scent exchange). It makes cats feel like they are part of a family of friendly cats which also applies to humans as cats often deposit scent on our lower legs with their cheeks and flanks.
The infographic covers one aspect of new cat introductions. There are others which I cover in other articles some of which are listed below with links and pics.
