Why are bogies green? Are boys smellier than girls? Does everybody fart - even teachers? Dirty Bertie - the boy with nose-pickingly revolting habits - is back! Join him as he tours the human body to discover the weird, wonderful and plain yucky things happening right under our noses. From bad breath, smelly sweat and blood-sucking nits to funny bones, amazing brains and bionic burping, this book includes some delightfully disgusting details guaranteed to put you off your dinner!