Meowfest: Cat Whisker Activity
Have you ever seen a cat investigate a space they’re interested in by putting their head in the space, only to back up and change their mind? A cat has a built- in measuring tape that lets them know when their curiosity may just get them stuck in a space that is too small for their bodies—their whiskers. A cat’s whiskers are the same length as the width of their body. They have small heads, which means going into a space head first without knowing if the rest of their body will fit can be problematic. Luckily, they know if their whiskers touch or bend upon entering a space, it is too small for their body!
Let’s Investigate
You can create a set of cat whiskers with a few items at home that can help you get a hands-on look at how a cat uses its whiskers.
Materials Needed
Directions
- Twist pipe cleaners together to form a set of whiskers. Trim them into desired length, but make sure they are symmetrical—meaning they are the same length from the center to the ends on both sides.
- Tape the center of the whiskers to the ball.
- Use the ball and whiskers and see if it can fit through tight spaces just like a cat. If the whiskers touch the sides of a space, bend or get pushed back, the space is too small for a cat!
Collect Data
Take notes, or pictures on where your cat whiskers will fit. What spaces would your imaginary cat be able to fit into and where would your cat need to back out of?
Meowfest: DIY Cat Toy
Meowfest: Museum Scavenger Hunt
If you visit the museum in the near future, prowl around for these favorite feline finds!
Meowfest: Why Do Cat Eyes Glow in the Dark?
Have you ever walked around a dark corner only to be surprised by glowing eyes staring back at you? The glowing eyes of a cat at night can sometimes be shocking and even a little scary if unexpected. Ancient Egyptians believed cats captured the glow of the setting sun in their eyes and kept it safe until morning. Ancient Greeks believed there was a light source inside the eyes that was like a gleaming fire. We now know that cat’s eyes appear to glow because they, along with the eyes of many other nocturnal animals, reflect light.
All eyes reflect light, but some eyes have a special reflective structure called a tapetum lucidum that create the appearance of glowing at night. The tapetum lucidum (Latin for “shining layer”) is essentially a tiny mirror in the back of many types of nocturnal animals’ eyeballs. It basically helps these animals see super-well at night. It is also what causes the glowing eye phenomenon known as “eyeshine.”
How Does It Work?
When light enters a cat’s eye, it can take a few routes. Some of the light directly hits the retina, a layer at the back of the eyeball containing cells that are sensitive to light. These photoreceptor cells trigger nerve impulses that pass via the optic nerve to the brain, where a visual image is formed.
Some of the light passes through or around the retina and hits the tapetum lucidum. The tapetum lucidum reflects visible light back through the retina, increasing the light available to the photoreceptors. This allows cats to see better in the dark than humans.
In the last route, some of the light that bounces off the tapetum lucidum, misses the retina, and bounces back out of the cat’s eyes. This reflected light, or eyeshine, is what we see when a cat’s eyes appear to be glowing.
Do Humans Have a Tapetum Lucidum?
Though our eyes have much in common with cats’ eyes, humans do not have this tapetum lucidum layer. If you shine a flashlight in a person’s eyes at night, you don’t see any sort of reflection.
The flash on a camera is bright enough, however, to cause a reflection off of the retina itself. This is the infamous “red-eye” in photographs. What you see is the red color from the blood vessels nourishing the eye.
Activity
In this two-part activity, you will be able to see how the tapetum lucidum works and then simulate how this reflective layer helps cats see well at night.
Materials Needed
Directions
- Make about a hole in your paper or cardboard using a pencil or pen. It does not have to be perfect! If using a thinner paper, try folding it a few times before making the hole (the harder it is to see light through, the better!).
- Hold the cardboard about 6 inches away from a blank wall and shine the flashlight through the hole toward the wall.
- Without looking directly into the light, glance at the side of the cardboard facing the wall. Take note of what you see.
- Repeat steps 2 and 3 while using your mirror instead of a wall. Again, avoid looking directly into the light or its reflection in the mirror! Note the difference in light on the side of the cardboard facing the mirror.
Imagine that the cardboard is a retina and the mirror is a reflective layer like the tapetum lucidum. What happened to the “retina” when the mirror was used instead of the wall?
This experiment shows how the amount of light from a singular light source is doubled when a reflective layer is present. Thus, it shows us how having a reflective layer—like a tapetum lucidum—increases the amount of light information available.
Materials Needed
Directions
1. Place your glass container about 6 inches away from a wall.
2. Shine your flashlight through the glass toward the wall and observe how the light appears on the wall.
3. Fill the container with water and place in the same spot as before.
4. Shine your flashlight through the glass toward the wall and observe how the light now appears on the wall.
Imagine that the wall is the retina and the water is a reflective layer like the tapetum lucidum. How does the reflective layer change the presence of light on the retina?
While this experiment is technically showing how light refraction works in water, it can also show us how having a reflective layer—like a tapetum lucidum—increases the amount of light available to cats’ eyes. Also, that the extra reflective light is not as clear as the original light input.
Jurassic Days: Specimen Scavenger Hunt
Carnegie Museum of Natural History has many type specimens in our collections. A type specimen is the name bearing specimen of a species. That means that that specimen was the first to be identified and named as a unique species. In Dinosaurs in Their Time there are 12 type specimens on display. Learn a little more about them below and the next time you visit see if you can find them all!
Redondosaurus bermani
Redondosaurus bermani lived during the Triassic period. While this animal looks like a large crocodile, it is a phytosaur, or an animal that closely resembles a crocodilian, though they are not closely related. The specimen here is a skull.
Dolabrosaurus aquatilis
Dolabrosaurus aquatilis lived during the Triassic period. It was a small reptile and specimens have been found in modern New Mexico. lived during the Triassic period. While this animal looks like a large crocodile, it is a phytosaur, or an animal that closely resembles a crocodilian, though they are not closely related. The specimen here is a skull.
Ceradotus felchi
Ceradotus felchi was a lobe-finned lungfish that lived during the late Jurassic period. Though this species of lungfish is extinct, there are still several lungfish species that still exist today, including relatives of this species. The fossil on display is a tooth plate.
Hoplosuchus kayi
Hoplosuchus kayi is a tiny, heavily armored land crocodile that lived during the Jurassic period. This is the only definitive specimen of this species and it was discovered by a ten-year-old boy, Jesse York, in 1917.
Apatosaurus louisae
Apatosaurus louisae was a sauropod (long-necked) dinosaur that lived during the late Jurassic period. This species was once incorrectly called Brontosaurus. Only one Apatosaurus louisae skull has ever been found and it is in our collection, though the skull on display is a replica because the real skull is very delicate. Apatosaurus louisae got its name from Andrew Carnegie’s wife, Louisa.
Camptosaurus aphanoecetes
Camptosaurus aphanoecetes stood on display at the museum for over 60 years, embedded in the rock in which it was found and incorrectly identified as Camptosaurus dispar. When Dinosaurs in Their Time was renovated it was discovered that our Camptosaurus was a brand-new species!
Diplodocus carnegii
Diplodocus carnegii or Dippy, is our most famous dinosaur because numerous copies stand in museums around the world! This species lived in what is now the North American mid-west during the late Jurassic period. Dippy was discovered in 1899 and has been on display since 1907.
Tyrannosaurus rex
Tyrannosaurus rex is perhaps the best-known species of dinosaur. Our specimen was discovered by Barnum Brown, the assistant curator of the American Museum of Natural History in 1900. The Carnegie Museum of Natural History bought this specimen for $7,000 in 1941. T. rex lived during the Cretaceous period.
Opisthotriton kayi
Opisthotriton kayi was a large salamander that lived in what is now known as Montana during the Cretaceous period. The fossils shown here are skull fragments and vertebra (the bones that make up the spine). These are the only known fossils of this species.
Anzu wyliei
Anzu wyliei was a large oviraptorosaur that lived during the Cretaceous period and discovered by our own paleontologist at the museum, Matt Lamanna! The fragments here are original pieces of the skull, but even if they were put together, they would not form a complete skull.
Goniopholis gilmorei
Goniopholis gilmorei was a common crocodile found in the Morrison Formation, in the U.S. West, during the Cretaceous period.
Deinosuchus rugosa
Deinosuchus rugosa was a massive Late Cretaceous crocodile, growing up to 26 feet long and weighing 11,000 pounds. Like modern crocodilians, Deinosuchus was an ambush predator, waiting in shallow water for prey to pass by.