er "Big warrens"?, 10 maybe 15 holes ! Don't know your ground but assuming there are no weird underground conditions ,these are tiny,weeny ,baby buries. No problem. Just be sensible ,be quiet, start early in the day so if the worse happens and you have a lay-up you have plenty of daylight to keep watch in and for heaven's sake feed your ferret so its not hungry. You don't have to dig massive trenches if you use a liner if you learn to read the warrens via the line. You will learn a lot more about the multi-levels &twists and turns of rabbit workings by using a line