The Japanese giant hornet is large and fearsome, but it is not particularly aggressive unless it feels threatened. It has a venom which is injected by the 6.25 mm-long (quarter-inch) stinger and attacks the nervous system and damages tissues of its victims. Tests with mice find the venom not to be among the most lethal, having an LD50 of 4.1 mg/kg, which compares to the deadliest wasp venom (to mice) by weight of Vespa luctuosa at 1.6 mg/kg. The potency of the sting is due to the relatively large amount of venom injected. Being stung is extremely painful and requires hospital treatment. On average 40 people die every year of anaphylactic shock after having been stung, which makes the Japanese giant hornet the most lethal animal in Japan (bears kill zero to five people and venomous snakes kill five to ten people each year).