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Snakes. Let’s learn about snakes! What kind of skin do snakes have? How do snakes move without legs? How do snakes reproduce? How do snakes eat things.

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Presentation on theme: "Snakes. Let’s learn about snakes! What kind of skin do snakes have? How do snakes move without legs? How do snakes reproduce? How do snakes eat things."— Presentation transcript:

1 Snakes

2 Let’s learn about snakes! What kind of skin do snakes have? How do snakes move without legs? How do snakes reproduce? How do snakes eat things larger than them? How many people get bit by venomous snakes? Snakes vs. Humans Snakes as Pets The end to snake myths!

3 Snake skin is dry, not slimy as most people think. The skin, which is covered by horny scales usually sheds several times a year.

4 Can you imagine moving around with no arms or legs? Of the four ways in which snakes can move, serpentine locomotion, a simple crawl, is the most common and the fastest. The snake contracts its muscles to produce a series of waves in its body, pushing from the back of each wave to move forward. Snakes also use serpentine locomotion to swim. In rectilinear, or caterpillar, movement, a heavy snake uses enlarged belly scales to grip the ground. Rectilinear movement is especially useful for moving through narrow burrows. Both rectilinear and concertina movement, a third method in which the snake pulls itself forward by bunching and lengthening its strong muscles in a spring like manner, are useful for climbing. The least common kind of locomotion is that of some desert-dwelling snakes. Called side winding, this motion involves lifting a loop of the body clear of the ground as the snake moves sideways. Side winding keeps the snake from slipping in loose sand. © Microsoft Corporation. All Rights Reserved.

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6 How snakes reproduce Snakes produce offspring in 2 basic ways: The first involves development of the fertilized eggs within the body of the female. When the embryos are fully developed, the offspring are born, appearing like miniature adults. Boa constrictors, water and garter snakes, and rattlesnakes are live bearing species and are considered ovoviviparous. The second method involves deposition of oblong, leathery-shelled eggs within the environment, where the eggs incubate. At the completion of embryonic development, the eggs hatch, producing miniature adults. Pythons and rat and mild snakes are egg layers, and are considered oviparous. In either case, the newborn or newly hatched can fend for themselves and receive no parental nurturing.

7 Why can snakes eat such LARGE animals? Small snakes feed on insects and larger ones on proportionately larger animals. Their teeth are designed for catching and holding prey, but not for chewing. The construction of the jaws, the ribs, and the expandable skin enable them to swallow very large prey whole. Some snakes capture animals by pinning them to the ground; some—the constrictors—crush them by wrapping their bodies around them and squeezing; still others—the venomous snakes—inject poison into their victims. The poison, or venom, is produced by modified salivary glands from which it passes through either a groove or a hollow bore in the fangs, the enlarged, specialized teeth found in venomous snakes. A snake may bite a person when threatened or alarmed; if the snake is venomous the bite can sometimes prove fatal. Only by familiarity with the appearance of particular species, or by examination of the fangs, can the venomous snakes be distinguished from the harmless ones.

8 Snake jaws Look at the difference between a set of snake jaws and human jaws.

9 Detecting prey Snakes' tongues, which are seldom still, play an important role in this sense. The tongue flicks in and out through a notch in the front of the upper lip, and the flicking becomes more frequent when a snake is exploring. When extended, the tongue tip waves up and down and odor particles adhere to it. When the tongue is withdrawn into the mouth, the odor particles are transferred to the roof of the mouth near a pair of duct openings leading into a special olfactory chamber, the Jacobson's or vomeronasal organ, which lies below the larger olfactory chamber. Snakes also smell through their noses. Airborne odors are sniffed or breathed in through the nasal passages (also paired, as are the vomeronsnasal organs) into the olfactory chambers. Both the olfactory chambers and the Jacobson's organs have patches of sensory cells, and the chemical reaction of odor particles with the cell surfaces is registered as nerve impulses, which are sent to the brain for interpretation. The sense of smell is of particular importance to snakes in tracking the paths of other snakes; for instance, males need to track females, and vipers must first envenomate and then track their prey. A snake's locomotion involves pushing against objects, which then bear odor signatures on only one side, the side pushed against. When a second snake passes the same way, one of its tongue tips picks up more odor particles than the other tip, indicating whether the left or right surface of a series of objects was touched by the earlier snake. Thus the tracking snake can identify the first snake's direction.

10 How common is it to get bitten by a venomous snake?

11 SnakeHuman How many legs do I have? 02 How do I smell?tongue nose How do I taste?Jacobson’s organ taste buds on tongue Do I chew my food or eat it whole? eat wholechew, then swallow

12 Pet Snakes Corn Snakes/ Rat Snakes corns are very tame and accept a fairly wide variety of environmental conditions. King Snakes/ Milk Snakes They are both hardy, docile species that make great pets. Ball Python They can be very tame and non-aggressive. But they are also known to be problem feeders, going off feed for long periods of time for no apparent reason.

13 Snake Myths The Myth: Milk Snakes sneak into barns and barnyards where they suck milk from cows. The Real Story: A milk cow would hardly stand still for having a Milk Snake's teeth clamped to one of her teats. But Milk Snakes do enter barns sometimes in pursuit of mice and other small rodents The Myth: Some snakes, such as garter snakes, swallow their young in times of danger in order to protect them. The Real Story: Garter snakes bear their young alive, as do some other kinds of snake. When born, however, the young are independent and they move away from their mother rather quickly. The Myth: A snake's skin is slimy and yucky, disgusting to touch. The Real Story: A snake's skin is dry and mostly smooth. Edges of the scales may make it seem a little rough. Many people find it pleasant to touch. The Myth: Rattlesnakes add a rattle each year. The Real Story: Rattlesnakes add a rattle each time they shed, and they can shed several times a year. Also, an individual may lose rattles as they break off. Therefore, counting rattles is not at all a way to tell a rattlesnake's age.


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