To the rousing theme of Grandstand, this quartet of white-shirted, black-tied lads (still not sure whether they're more idiotic or antlike?) race into the venue. For the previous few minutes, we've been looking at them on screens prancing around London, limbering up in their pants as they prepare for their Edinburgh run. When they finally make their entrance, it's weirdly uplifting and utterly daft all at the same time. It's truly fortunate that sketch show groups are still hell-bent these days on messing around with their chosen form rather than just writing drop dead funny set-pieces; and the likes of the Idiots are messing around with the best of them.

A mysterious and seemingly flat scene where a stand-up comic appears to be experiencing unwelcome spectral attention is later revisited with the sketch re-run with added spookiness. The bit where one of the Ants blandly serenades an audience member makes you wonder where it's all going: the answer is riotous. But for downright anarchic fun, the finale with the team of clown decorators being castigated for their health and safety record is nothing short of blissful. Whether the Ants/Idiots have moved on much from last year's highly praised debut seems to be a moot point. They have a solid identity and a sense of highly constructed fun that will be hard to beat this year. There's plenty time for them to develop themselves into oblivion.

Pleasance Courtyard, 556 6550, until 25 Aug (not 11, 18), 6.20pm, £8.50–£9.50 (£7–£8).