Michael Thrusfield writes in Veterinary Epidemiology (3rd Edition) about contiguous populations where individuals of the population meets with individuals of other populations thereby serving as mean to spread the infectious disease. Domestic animals such as cats that are not confined to a house belong to contiguous population. Cats move freely within cities, coming in contact with other urban, suburban and rural animals of their own and different species e.g. Bats.
Sour Relationship
When I think about her,
I sigh.
Indelible Memory
The first thought that crosses his mind on seeing her after all those years was that how much better it would be to replace her with her younger self.