Guineas are used to rid your yard of insects like ticks. Somehow they can find the smallest insect and eat it.

They tend to get out of the yard, though, so you need a good fence. They don't just wander away, they just wander and there is no telling where they might wind up. They do tend to stay in a flock, though, so when you find one you will find them all.

Peacocks are the best for making noise when a stranger comes up. They also attack but since they are not very bright you have to be careful they don't attack you. They can also fly, but they don't like to. They would rather stand their ground and get into a fight if something tries to attack them.