How do boa constrictors protect themselfs?

They use there squezzing power!!

^^^^ I left this answer to show how little information people are prepared to type in order to secure points !

Boas protect themselves by a painful (yet harmless) bite. They usually use a 'threat posture' rearing up and forming their body into an 'S' shape in readiness to strike. I speak from experience - having been bitten a few times by Boas !