This week, what's the bottom line on sanitising surfaces against Covid-19? Why, wonders Lester, am I so sluggish for the first few hours of the day? And can you train your chronotype to be a better morning person? Does it make a difference if you sleep on your left or your right? Why is gambling addictive and is addiction a genetic trait? Can pornography be addictive? And will resorting to apps like Google Maps impact my sense of direction? Join Dr Chris Smith and Lester Kiewit for the answers... Like this podcast? Please help us by supporting the Naked Scientists