Adder venom attacks the blood and nervous system.The venom of an adder bite is less toxic than that of a puff-adder, but it is far more toxic when injected intravenously.
The hognose snake，sometimes called the puffadder，is one of nature's clowns．Some people think that he is deadly poisonous．Actually，he's just a harmless fellow who spends most of his time huntingtoads．