As the weather warms and you start to venture outside, be careful where you walk. If you come across a purple fence post, it’s best to stay away.

A purple fence post is meant to send a message to anyone who comes across it, and that message is: No trespassing!

While property owners have the option of hanging a sign to indicate private property, signs can deteriorate over time while paint will last a lot longer and still convey the same message.

In 1987 Arkansas became the first state to implement a purple paint law. Currently, 22 states have laws allowing landowners to mark the perimeter of their property with purple paint.

However, while some states use different color paint – Idaho and Montana use orange paint – the idea is the same.