Getting kids to stay in bed can be a hard enough task, but what if you were looking after a pair of two-tonne rhinos? That's the dilemma keepers at Noah's Ark Farm Zoo near Bristol were facing, until one employee came up with a bright idea. The Bristol Post reports that Rumba and Rumbull, the zoo's 11-year-old white rhinos, were refusing to go to bed in the evenings as they preferred to play outside in their field instead. However, zookeeper Emma Green tried giving them an all-over scratch with a stiff-bristled broom to help the animals wind down. As rhinos have thick, leathery hides, they jump at the chance to have a good scratch - and this made them more receptive to the idea of settling down for the night. "Rumbull in particular has become so taken by his daily rub that he often rolls on the floor of his yard like a playful pet," reports the newspaper. A daily rub-down isn't the only creature comfort afforded to Rumba and Rumbull - the rhinos also get electric heaters to keep them warm during the winter, as they hail from the much hotter climes of South Africa.