By: Dr. Jerry Bergman
Montpelier, Ohio
As mentioned in part 1, Rats have poor vision, but their other senses are highly developed, especially their sense of smell, touch, and hearing.
Their complex nervous system and brain give them very sophisticated cognitive skills, including empathy, abstract rule learning, and advanced problem-solving. Rats also effectively communicate with each other by using body language like humans.
Rat brains are structurally so similar to human brains that, for centuries, researchers have studied rat brains to understand the details of the workings of our brains.
They navigate primarily by using their sense of smell, which responds not only to the common scents that all mammals rely on, but also can sense many chemicals that exist in the air. Rats breathe through their noses, causing the air to move past a patch of skin that is rich with smell receptors and olfactory neurons.
Smell particles called odorants bind to the olfactory neuron cilia, triggering a neural response. Rodents’ olfactory lobes are much more pronounced than in humans, making rodents’ sense of smell by far their most important sense organ.
Specifically, rats have 1,207 olfactory receptor genes, ranking them far above humans’ tiny 396 olfactory receptors. In comparison, dogs have only 811 olfactory receptors.
Rats have 1,207 olfactory receptor genes, making them critical in clearing landmines during human wars. Over 60 countries are contaminated with hidden landmines and other explosive remnants of war that cause tragic accidents and hamper communities from developing their productive land.
They use giant pouched rats, trained by a Belgian non-profit organization called APOPO, to use their exceptional sense of smell to locate the landmines. The rats are not heavy enough to trigger the landmine. When a rat finds a landmine, it scratches the ground at the location to signal its human teammates, who then can safely detonate the explosive.
Rats are also used to sniff for tuberculosis disease in humans. They are both more efficient and accurate than human microscopic evaluations.
Rats can successfully sense tuberculosis in 70 percent of cases in patients with HIV infections, whereas microscope laboratory testing is only 20 percent effective. Chemicals called pheromones are also a critical means of rat communication. They produce them as warnings of danger, or when scent marking to let other rats know they are near.
Rats also explore using their enormously sensitive whiskers to interact with their environment. They also have a second smell organ, the vomeronasal organ.
This organ is set in a thin, ovoid space in the lower portion of the nasal passage beside the septum. When rats sniff and taste, scent molecules dissolve in their mucus, which is then evaluated by their vomeronasal organ receptors.
Rodents’ front teeth, the incisors, continue to grow throughout their entire lives. Pet rats often experience overgrown incisors, a problem that can be avoided by giving them opportunities to gnaw, such as chew toys. They naturally habitually chew, so pet owners often provide wood pencils or sticks to gnaw on, both to relieve boredom and as entertainment.
Evolutionary History
The evolutionary history of rodents in North America, evolutionists claim, extends back to the Late Paleocene Epoch, which evolutionists postulate was 56 million years ago.
Fossil evidence of modern rats has been found as far back as the Pliocene Era. After decades of looking by paleontologists, as is true of most mammals, the fossil record has failed to reveal any evidence of their evolution from some putative non-rat precursors.
The explanation for this problem is: “the fossil record supporting rat evolution is poor,” meaning the fossils proving their evolution must exist, but we have yet to find them. In spite of over a century of looking, paleontologists have yet to find any evidence for their evolution from some putative non-rat. Paleontologists claim the reason we have no evidence of rat evolution is not only because of “the gaps in the fossil record” but also because of “the wide variations in dating.”
Therefore, the “lack of fossil evidence prior to the Late Paleocene makes the understanding of evolutionary relationships between rodents above the familial level a continuing quest.”
The reason we have no evidence of rat evolution is that they did not evolve from some non-rat ancestor. The evidence is clear: from the beginning of creation, rats have always been rats created on the same day mammals were created.
It is clear that they are marvelous creatures, even though many are forced to rely on digging through garbage to survive. This is not their fault, but the fault of living in a fallen world.
The popularity of rats is indicated by the book “The Rat” part of the Happy Healthy Pet Book, which claims that “rats are gentile, affectionate, clean and social with their own kind as well as with people…they are amazing creatures.”
As is true of most mammals, they exist in a wide variety of colors, sizes, and temperaments. The major problem with pet rats is their short lifespan, which is only from 24 to 30 months. For some people, especially children, the loss of a pet can be very difficult to deal with.
My wife holding our grandson’s rat.
Dr. Bergman is a multi-award-winning professor and author. Has 9 degrees and has taught at both the graduate and undergraduate level for over 40 years. His over 2,100 publications are in both scholarly and popular journals. Dr. Bergman’s work has been translated into 15 languages. He has spoken over 2,000 times to college, university and church groups in America, Canada, Europe, the South Sea Islands, and Africa. He lives in Montpelier and is available to present in churches and schools. Jerry can be reached at JerryBergman30@yahoo.com