Depending on the species, there are many different answers to this question, some of which are...
With no natural barriers the villagers could not protect themselves from other civilizations, animals and natural disasters.
they survive by natural selection. also they protect themselves
There are many reasons to protect yourself: from other animals who might want to kill and eat you, from the elements, from natural dangers like rockslides or earthquakes, or even from accidents.
Native americans lit fire in the wood to protect themselves from wild animals or make themselves warm.
how do animals protect themselves from their enemies by using there mouth parts
Manatees are a gentle giant and most the time they don't need to protect themselves Manatees have no natural predators only humans they can't stop a boat from hitting them so your answer is they don't protect themselves other than moving away from danger.
So they can blend in with their natural habitat and protect themselves from predators
by killing them
to protect themselves or to protect there family
WHEN THE WOODS AND THE BONES AND PARTS OR PLants.
In many movies, such as "Bambi", the mother animals teach their young how to survive but in reality, the animals are born with a natural instinct to protect themselves.
the ottawas proteced themselves by rubbing themselves with animals fat.