This is the single most important thing you can do. If you give termites something easier to find than a way into your house, they will find these monitors so you can add bait which they take back to kill off their colony. The more monitors the better. If your home is worth defending, and it is, you should do it with plenty of monitors. Three meters apart is the average; some close to the building others near the fence. A few across the front, few down each side and more around the backyard easily add up to over 20.
Checking monitors and checking your home is so easy you could become blasé.
Termites count on that.