Cats are a natural predator to rodents and snakes. Must have, IMO.

@Marz You are sadly misinformed.

One of the World's Biggest Extinction Crises Is Being Caused by Cats [news.vice.com].

Tiny cams reveal that US domestic cats are killing more than 4 billion animals per year, including at least 500 million birds, and the reason why one in three American bird species are in decline.
[treehugger.com]

Toxoplasma parasites force rats to seek out cats to complete their cycle
[t.co]

Cats carry a dangerous parasite that can live 3 months in feces, lie dormant in human brains, infect wildlife -[t.co]

@birdingnut My fault for not specifying the conditions for cohabiting with cats. I wasn’t referring to rampant, non-neutered, feral cats without vaccinations. Military bases in combat zones have vets who tag, track and care for cats whose sole purpose is to keep unwanted critters and reptiles out of the base (structured and gated, unlike a camp). Effective in that respect.

@Marz If you read the articles, or at least the links, you'll see that cats carry deadly diseases and the only reason they catch mice is because the toxoplasma parasites need cats in their life cycle, so they force infected mice to show themselves to cats and act tame.

When the cats consume the mice, they become infected and pass on the parasite. They can stay in cat feces for three months, and infect wildlife.

Cats aren't EVER "needed" to kill animals. As for snakes, any snakes found in US houses would have to be harmless black rat snakes, hunting mice.
You should read the provided links for yourself before commenting.