different reptiles have different defences.for example,the tiger salamander secretes the samonella virus out of its back.many lizards can constrict the bloodvessels in their tails and release a section of it without bleeding.some lizards can change colour in order to blend in with their surroundings.some lizards can puff-up a flap of skin under their chins(dewlap)in order to make them appear larger.the basilisk lizard cad run on water to escape.lizards also bite!in the end,it seems that their best and most used defense is being sensitive to movement and running in the other direction.