Well, obviously, the answer is a large family. I have 12 kids. Keeping watch should be easy. Dogs can help. There is a trade-off to be had. Larger dogs can act

Well, obviously, the answer is a large family. I have 12 kids. Keeping watch should be easy. Dogs can help. There is a trade-off to be had. Larger dogs can actively participate in defense, but they require lots of food. Geese might be a better option; they seem to be happy eating grass.