Matt got in touch with this question: "Do all humans have the same number of nerve endings in their skin, and if so, do those of us who are bigger, either taller or fatter, have reduced sensitivity in a given area of skin?" Eva Higginbotham spoke with Professor Francis McGlone from Liverpool John Moores University to feel out the answer... Like this podcast? Please help us by supporting the Naked Scientists

Pavel asked us "On one of the Naked Scientists programmes it was mentioned that a newborn baby has initially sterile intestines and gets most of its microbiome during the passage through the uterus and vagina. What happens to children that are brought into this world via caesarean?" We reached out to Peter Brocklehurst from the University of Birmingham to find out... Like this podcast? Please help us by supporting the Naked Scientists

Listener Jon sent us this question: "I just purchased some dart frogs which need to live in high humidity conditions. In order to attain this we basically sealed off the terrariums. The question is whether a really sealed terrarium could provide enough oxygen for the frogs through plant photosynthesis alone. Who would win: the frogs or the plants?" Phil Sansom got the answer to this 'pet peeve' from plant scientist Stephanie Smith... Like this podcast? Please help us by supporting the Naked Scientists

Fusion could be the most sustainable source of energy in the future. But how much can we get out of it? Like this podcast? Please help us by supporting the Naked Scientists

Dogs come in all sizes, from tiny Chihuahuas to giant Great Danes. Their head size is hugely different, as must be their brain size. Does this mean that a Great Dane is massively more intelligent than a Chihuahua? Like this podcast? Please help us by supporting the Naked Scientists

Is a kitchen sponge full of bacteria, and will a microwave kill them? We tested this at home and asked an expert! Like this podcast? Please help us by supporting the Naked Scientists

Listener Robin asks: "I heard on the podcast, that the reason why we get a sunburn, is that the body is trying to fix cells that are damaged by UV radiation. So if one person is sunburned longer than another, does that mean their immune system is worse?" To find an answer to this burning question, Adam Murphy spoke to dermatologist Jane Sterling... Like this podcast? Please help us by supporting the Naked Scientists

Listener Ray asked us: " The Earth has apparently reversed its polarity fairly regularly, and is perhaps overdue for the next instance. Is anything known about how this will happen, and the effects? How will it affect our reliance on technology?" We put Ray's question to Richard Harrison, Head of the Department of Earth Sciences at the University of Cambridge, and he gave us a flipping good answer... Like this podcast? Please help us by supporting the Naked Scientists

Jure asked us "Why doesn't a woman's body reject sperm as a foreign object?" Phil Sansom sought out the answer, by speaking to doctor and sexual health consultant Graham McKinnon... Like this podcast? Please help us by supporting the Naked Scientists

Listener Derek got in touch with this question - "I can sit at my work desk, with my phone by my side, and the signal strength display goes from saying "no service" to 4 bars out of 5, within a couple of minutes, for no obvious reason. It varies like this all day, every day. I can understand why some places have good coverage, and others have bad coverage, but why should it vary so much in one place?" We asked signal expert Ramsey Faragher from Focal Point Positioning and Cambridge University to dial up an answer to Derek's question about wandering mobile phone bars... Like this podcast? Please help us by supporting the Naked Scientists