That was two to three times higher than grassland and woodland.

Until now, little has been known about which habitats are best for the furry yellow-and-black insects and experts hope the finding will aid conservation work.

Britain once had more than 25 native species of bumblebee, but three of those have been lost in the past 50 years and several more are under threat. Scientists blame the decline on modern farming methods that have deprived bumblebees of many traditional flowering plant food sources.

Gardens, by contrast, have plenty of flowers and good nesting sites -- particularly messy ones, according to lead researcher Juliet Osborne from the Rothamsted Research centre in central England. Favourite nesting spots include undisturbed flower beds and compost heaps.