More than 6,000 homes are burgled each year because thieves have easy access to the property's keys, new data has revealed.
Almost a third of Brits often leave a spare key hidden outside their home, according to official Police data obtained by insurer LV= under a Freedom of Information Act.
Nearly a fifth of householders leave a key under a plant pot, while 13% hide a key under their outdoor bin. Other popular hiding places are rocks or stones (13%), doormats (10%) and under a garden gnome or ornament (8%).
People tend to leave a key outside so that friends and family can gain access to their property while they're away from home – 25% admitted leaving one hidden in case of an emergency, while a similar number (23%) left a spare key in case they lost their own key.
But it's not just keys left outside the home that are a draw for burglars: people also leave keys inside where a thief could reach them through a letterbox or open window.
Some 18% of Brits leave their keys close to the front door – in a bowl, hook or on a table, for example – giving burglars the opportunity to hook them out and break in.
And in some cases, householders don't even bother locking the door – a fifth of Brits leave their front of back door unlocked when they're out.
Lost keys also pose a potential threat of burglary, with nearly 20 million spare keys currently unaccounted for. On average, each household loses two keys that were cut for friends, family or people working in their home.
Commenting on the findings, Selwyn Fernandes, managing director of LV=, said: "While the number of burglaries is falling overall, it is alarming to see that the number of thefts where the burglar used a key is increasing. Burglars know that people tend to leave a spare key in a handful of places near their door and will often search these before attempting a break in.
"Don't make their job easier for them by leaving keys where they can easily be accessed. If you must leave a key outside, use a Police approved key safe and only give the code to people you trust."