This is one for Steve really, and maybe sarahc if she is on this bit of the forum. When you cull your mice under the age of about 12 days, are there any tricks you use to make sure it works every time? Obviously all you usually hear is 'chuck em at a hard surface' which is not really too helpful. Do you hold them a special way or avoid doing it a certain way for example? Also what are the pros and cons, what's it like etc?