Most of these hosts do all they can to ensure their guests have the best experience.
And it's... not an easy job sometimes. At all.
Here are 8 of the weirdest things guests have done and, er, forgotten in their holiday rentals.
Watch: Tips from savvy travellers. Post continues below.
'Poop, raw meat, and a used condom.'
"My mum lets out a room in her house and she's found some random (and gross) stuff. One guest left half a tray of raw mince in the bar fridge (note: they did not use the kitchen at any point in their stay). People also frequently leave without flushing the toilet (we're talking number twos) – but the worst was when I was helping her clean once after someone had stayed for a bit of a longer stint, and pushed the bed aside to vacuum only to find a dried condom stuck to the wooden floor…" – Laura.
'I found a cat.'
"[I found] a cat that hid behind and under the fridge. [The] people left thinking it had escaped out the door. It didn't appear for a few days. A guest who found it left me a nasty review saying I had 'clandestinely hidden a cat in the room'. Sent cat back via air shipment. [The guests were] two doctors that never really said 'thanks' for all we went to to get their cat back to them." – Anonymous, Quora.