i have 13 guineas of all ages right now,,they grew up with chickens of every age,,,i get them at 1 day old,,and once outside,,,they can go wherever from day 1,,,what usually happens is,,,,after they get big nuff to fly,,,for a month they fly over the fence,,,and then run back and forth trying to get back in,,haha
the only place in my fence where it looks like theres a "trail",, is on the outside,, from them.
mine dont go farther then they can hear my chickens,,,,they go next door and chase people from "their" corner,,,,the business next door thinks its funny as can be. i used to feed all my birds in the evening to "make sure" my guineas always came back,,,but i dont do that any more,,,, they fly to the "outside" of the 4 foot fence,, and scream at me to let them in,, about 1/2 hour before its time for me to close em up.