Why do snakes bite?
When a snake bites, it injects venom to immobilize its prey. As humans are too large for a snake to eat, most snakes bite in self defense.

Snake bites often occur when a person accidentally steps on a snake while out walking. However, sometimes people are bitten when they deliberately provoke a snake by striking it or trying to pick it up.
Considerations
Snake bites can be deadly if not treated quickly. Children are at higher risk for death or serious complications due to snake bites because of their smaller body size.

Causes
Poisonous snake bites include bites by any of the following:
Cobra
Copperhead
Coral snake
Cottonmouth (water moccasin)
Rattlesnake
Various snakes found at zoos
All snakes will bite when threatened or surprised, but most will usually avoid people if possible and only bite as a last resort.
Snakes found in and near water are often mistaken as being poisonous. Most species of snake are harmless and many bites are not life-threatening, but unless you are absolutely sure that you know the species, treat it seriously.
Symptoms:
Symptoms depend on the type of snake, but may include:
Bleeding from wound
Blurred vision
Burning of the skin
Convulsions
Diarrhea
Dizziness
Excessive sweating
Fainting
Fang marks in the skin
Fever
Increased thirst
Loss of muscle coordination
Nausea and vomiting
Numbness and tingling
Rapid pulse
Tissue death
Severe pain
Skin discoloration
Swelling at the site of the bite
Weakness
First Aid:
1. Keep the person calm, reassuring them that bites can be effectively treated in an emergency room. Restrict movement, and keep the affected area below heart level to reduce the flow of venom.
2. If you have a pump suction device (such as that made by Sawyer), follow the manufacturer’s directions.
3. Remove any rings or constricting items because the affected area may swell. Create a loose splint to help restrict movement of the area.
Do NOT allow the person to become over-exerted. If necessary, carry the person to safety.
Do NOT apply a tourniquet.
Do NOT apply cold compresses to a snake bite.
Do NOT cut into a snake bite with a knife or razor.
Do NOT try to suck out the venom by mouth.
Do NOT give the person stimulants or pain medications unless a doctor tells you to do so.
Do NOT give the person anything by mouth.
Do NOT raise the site of the bite above the level of the person’s heart.