Gender and being allowed into the bedroom do not appear to be linked to allergies, whereas there does appear to be a link between colour and allergies, perhaps due to the composition or thickness of cat hairs. The researchers observed 81 cats for three months, and found that the female cats had relationships with as many as 10 toms over three days. Cat society used to be organised round controlled polygamy, with each male controlling a patch and permitting two or three females onto his territory. Female cats chose their areas according to the abilities of males to produce high quality kittens. Changes in the urban environment have changed cats' behaviour.
Food is more plentiful, and feral domestic cat populations have grown to high densities.
The discovery was reported in 'The Veterinarian', an Australian journal, issue for Sep 1999. It is unclear whether the method is humane, or what happens to cats that do not eat a lethal dose. Chemical neutering may be a better way of tackling the problem of feral cats. The cat is drawn to rub a cheek against an object where the mix has been wiped, rather than the cat spraying the object, or location, with urine. The mix includes aminovaleric and caproic acids, and can be produced as a stick, paste or spray.