Christopher Trace and Valerie Singleton introduce a magazine programme for younger viewers.

In Blue Peter at 5.0
If you have ever watched "It's a Square World," Michael Bentine's programme, it is likely that you have seen him grappling with the Bumblies. They are little creatures, with twittery voices and rapid movements, who pop up at the most awkward moments - during a lecture or a song - and take over the programme with their antics and furious energy. You must have wondered about them - where they come from, and how they get in. Today you may have a chance to find out because Michael Bentine himself is coming along to talk about them. We say "may" advisedly, because with Bumblies you never know what can happen!