You can use pendulems to find wells, stones, sex of babies, also you can actually sit at a map and locate people or to give you an idea where they may be. Dowsing rods, you can make simply from coat hangers, form a L, make 2 of them, one for each hand.
After you have them finished, one side is longer then the other, hold onto the shorter side, supporting it, try not to allow grasp to loose, and ask a question, like your name. If you ask the dowsing rods if your name is (and pick 3 names for example) say, Bob and with the other names it did nothing, yet with the correct name, Bob, the rods will turn towards the center and cross - possibly circle too.
Now, once you have become secure with them, you can use them to find water lines, septic tank covers (that was the last time I used mine ...dig it up for the honey pot :0) ), minerals anything you choose.
When looking for water, its dowsning, when you are looking for other things, its devining. You can ask any question, basicly yes and no. Using that as a fun, not fact, although it is interesting! If all else fails its a hobby, I do help with finding wells, never take money as its not always 100%, but it is fun! Also with pendulems(sp) you can hold it, allow it to be still and then begin asking how deep do we did, 10 ft, 20 ft, 50 ft, etc. when the pendulem circles (for me) then that is the number of feet.
Also I have seen a woman use a straight tree branch, hold it with both hands firmly and the branch will roll. (never worked for me, but I was in aw over it)
Good luck on your egg sexing! Can't wait!