Great Unanswered Questions - Series 2 - Episode 4

Sometimes there isn't an obvious answer to an obvious question but this won't stop comedians Ardal O' Hanlon and Colin Murphy pressing resident nerds Dr David Booth and Matthew Collins to find out the answers to questions such as; why do people kiss? Why do pizzas come in a square box? And, do snails think slowly? You may not get the answers you were expecting but you'll certainly have a few laughs.