Can snakes poison themselves?

Naturalists are agreed that venomous snakes are immune to their own poison when it is swallowed. There is a difference of opinion, however, as to whether snakes are susceptible to their own poison when it is injected into their blood. The late Raymond L. Ditmars believed they were not. On the other hand, reputable authorities state that rattle-snakes are susceptible to their own poison and sometimes cause their own death by biting themselves. There is a possibility, however, that in such cases the fangs may puncture the spinal nerve or some vital organ and that death may not be due primarily to the venom. It is doubtful, most snake experts say, whether any snake ever commits intentional suicide. Snakes are not likely to bite themselves unless they are infuriated or severely injured and are unable to wreak vengeance on their tormentors. Some authorities suggest that venomous snakes may have a certain resistance to their own venom when injected into their blood but not to that of other snakes even of the same species.