Beware of snake!

Just on the outskirts of the city, one can easily find poisonous snakes - usually coral snakes to be exact. They are usually the main reasoning behind the trimming of grass and maintaining of landscaping, lest you be walking through your "natural" yard one morning and step on one, resulting in death. It's also a good reason not to just go walking into someone's private property if it's not regularly maintained. This sign is one of several strung up around some beach front property that appears to owned but not lived on - "soon to be developed." Between this and the barbed wire everywhere, I can only assume they mean to keep out squatters or others who might think "hey, let's go check this place out because no one lives there." The question remains as to if the owners mean to warn against wild snakes that might be in the property or a snake they put there themselves to protect the property, because the wording here "careful snake" (or more colloquially "beware of snake") is similar to the "cuidado cãe" (more less the USA equivalent to "beware of dog").