Why cockroaches invariably are found dead on their backs; what happens to old and previous Covid-19 variants; why do I see myself differently in photographs compared with when I look in the mirror; how do chickens produce eggs; what powers deep space probes; why do some people snore, especially after a few drinks; and why is yawning contagious? Dr Chris Smith and Lester Kiewit have the solutions! Like this podcast? Please help us by supporting the Naked Scientists