I think we can all agree with Nige regarding millipedes vs. dung, but what struck me was this: "It's a rare snapshot of evolution caught in the act." Some beetle or beetles must have been pioneers in the killing and eating of millipedes, in the course of which subtle changes in head and neck came about, which were then passed on. Do I have that right? Is this the inheritance of an acquired characteristic? Because surely they are not suggesting that the subtle changes came about and then the beetles started eating the millipedes. How would the beetles know that developmental changes have taken place in their anatomy making it unnecessary for them to eat the traditional dung? I would also think dung would be about as common a food source as is imaginable, obtainable in greater abundance than millipedes and easier to get at.