The way of animals can be very different from that of humans. One of my earliest experience of an interaction with lizards was when I stepped on the floor from the bed and when my feet touched the ground, there was a sensation of something soft and icky. It turned out that there was a lizard on the floor and my toe had stepped on the tail. The tail detached itself and started hopping on the floor for some time, which was something very weird to watch.
In this case, a person found a snake in their courtyard which was a venomous snake, a rattlesnake. The guy cut off the snake's head with a shovel, and the head became separate from the rest of the body. 10 minutes later, having figured that he had given the snake enough time, he went to dispose off the head, but when he tried to catch the head, the head bit him and injected venom in him for a period of 30 seconds, enough time to inject a large amount of venom. According to experts, in such a situation, when the snake is dying, it injects more venom than normal. The wife hurried him to hospital, and eventually he was injected with many vials of anti-venom saving his life although there are still many complications that he is suffering, along with the medical expenses not covered by insurance (
link to article):
Jeremy Sutcliffe, a 40-year-old Texas native, found this out the hard way. He and his wife, Jennifer, were outside doing yard work on the morning of May 27 when Ms. Sutcliffe discovered a four-foot-long, dirt-colored rattlesnake in their garden. She screamed. Her husband abandoned his lawn mower and ran to her, grabbing a shovel and lopping off the creature’s head with a single swing.
After about 10 minutes, her husband tried to dispose of the snake’s severed head, Ms. Sutcliffe, 43, said in an interview. When he reached down, the snake — a Western diamondback — sank its fangs into his hand and held on for about 30 seconds.
“Finally he got the snake head pulled off,” said Ms. Sutcliffe, who is a nurse. “I called 9-1-1 and just started driving because I didn’t know where to go exactly, what hospital carries antivenom.”
This is not the first time that this has happened, such incidents have happened to other people in the past, although very infrequently.