While the Ronald Harwood season continues at the Duchess, the stage has been commandeered for morning and (on Sundays) matinee performances of this popular story  by the outgoing Children’s Laureate Michael Rosen, ideal for anyone three years old and upwards.

Quite a few two year-olds survived the bear hunt, too, as Dad and the kids, and baby and dog, tramped through various terrains, sang songs and found a bear in a narrow, gloomy cave before hurrying home to bed with their nursery teddies.

There’s no attempt to reproduce the glorious colour wash of Helen Oxenbury’s illustrations for Rosen’s 1989 book by the director Sally Cookson and designer Katie Sykes (their adaptation was first seen at the Bristol Old Vic three years ago).

Instead, we have a curtain of shiny green strips for the long grass, a blue river of towels, pails and watering cans, a squelchy art class of brown paint and Tyrolean yodelling for the muddy swamp, a pile of cardboard boxes in the dark forest and a snowstorm of a billowing sheet and handfuls of fake flakes.

It’s all very simple and ingenious and put across with a genuine Blue Peter niceness by the bespectacled quartet of Duncan Foster (as Dad), Gareth Warren, Victoria Andrews and Bob Karper as a furry-eared, guitar-strumming canine. And we all get wet in the river, as they squirt us with water pistols; one mum put up a brolly in the stalls.

The bear itself is a bit of a non-frightening disappointment, but the cast have no qualms about revealing Dad inside the skin, pulling the strings, and no three year-old was remotely fazed by this Brechtian sleight of hand.

Benji Bower’s music and lyrics are catchy and melodic, and we all joined in the chorus with minimal coercion: “What a beautiful day … we’re not scared.”  The rapt expressions on the little shining faces all around me were worth the price of my free ticket alone.