Although cats may breed throughout the year, particularly in warmer climates or if they are reared as indoor cats, spring through to late summer is the time of year when most kittens are born because female cats usually come into heat, or oestrus, from late winter through to summer. This means that the birth of kittens coincides with longer day lengths at a time when food sources are abundant and they therefore have a greater chance of survival in the wild. Because there is a surge in kitten numbers over the warmer months, many sadly end up being euthanized since there simply aren't enough people willing to take them on as pets.
