with Johnny Morris and TERRY NUTKINS
How do gorillas keep fit? At a zoo in Kent they have their own gymnasium. Johnny arrives for a visit and becomes involved in a pretty strenuous work out.
For his exercise Terry climbs up on to Dartmoor to track down the shyest and the hardiest of the famous breed of local pony.
Back in the studio, Johnny and Terry marvel at some of the feats achieved by animal builders. For example, prairie dogs live in burrows that are susceptible to flooding, yet they have devised a clever way to keep themselves dry.
Producer ROBIN hellier BBC Bristol -