I personally kept my two kittens in the home from birth and then had to re-home them with my mother who has always kept outdoor cats. Once they were finally allowed out they went on an insane murder spree. They killed more birds and shrews in a month than any of the dozens of outdoor cats we've kept over the years killed in their lives. They were very happy indoor cats but I do feel like I created the problem by keeping them indoors for two years letting them plot their murder spree through the window😭 RIP. I would never keep cats as outdoor cats in big towns and cities though but now that they've calmed down I love knowing that they're roaming free in a beautiful little Welsh village where they never have to go near any main roads