However, as worms do not have morphologically distinct ear organs, these animals are presumed to be insensitive to airborne sound and thereby lack auditory sensation, which represents the only primary sensory modality absent in C. elegans.
And the vast majority of invertebrate species are thus believed to be sound insensitive.” The scientists discovered, however, that worms responded to airborne sounds in the range of 100 hertz to 5 kilohertz — a range broader than some vertebrates can sense.
Earthworms have no eyes or ears, but they have light-sensitive cells that help them tell the difference between light and darkness. Their bodies are sensitive to vibrations�and worms may "outrun" the shovels of anglers digging worms for fish bait!
Hearing: Earthworms have no ears, but their bodies can sense the vibrations of animals moving nearby. Thinking and feeling: Worms have a brain that connects with nerves from their skin and muscles.
Most worm charming methods involve vibrating the soil, which encourages the worms to the surface. In 2008, researchers from Vanderbilt University claimed that the worms surface because the vibrations are similar to those produced by digging moles, which prey on earthworms.
It's only been discovered in vertebrates and some arthropods. And the vast majority of invertebrate species are thus believed to be sound insensitive.” During the study, scientists played a tone with the range of 100 hertz to 5 kilohertz. They found that worms quickly moved away from the source of the sound.
But animals with simple nervous systems, like lobsters, snails and worms, do not have the ability to process emotional information and therefore do not experience suffering, say most researchers. "There are two types of animals, invertebrates and vertebrates," said Craig W.
A web site for fans of earthworms tackled the question recently: Yes, it is now accepted that worms feel pain – and that includes when they are cut in half. They do not anticipate pain or feel pain as an emotional response, however. They simply move in response to pain as a reflex response.
Invertebrates cover a range of creatures from insects and spiders to mollusks and crustaceans. Farstad said most invertebrates, including lobsters and crabs boiled alive, do not feel pain because, unlike mammals, they do not have a big brain to read the signals.
Conclusion: Mealworm respond to different sounds in different ways possibly due to the different waves from each sound affecting them differently. Mealworms seem to dislike sounds with very strong vibrations, like the tuning fork.
Earthworms have a simple brain that connects with nerves from their skin and muscles. The nerves detect light, vibrations and even some tastes.
Cutting a worm in half is pretty brainless, but not as much as our earthy friends. Earthworms (Lumbricus terristris) are annelids and have a very simple nervous system, with a single nerve cord running the length of the body and side branches for each segment and no brain.
Worms don't sleep on a day/night schedule like mammals. Instead, their sleep-like behavior occurs at specific stages during development; the worms enter this state each time they transition from one larval stage to another.
The group found that earthworms produce two kinds of chemical — enkephalins and beta endorphins — which have been Identified in human brains as similar to opiates in their ability to affect sensations of pleasure and pain.
The new findings suggest that even worms may suffer from anxiety and eating disorders.
"We show that worms exhibit environmental familiarisation, and that this memory persists for at least 14 days -- long enough for the brain to regenerate," write the authors.
Further research showed that the signaling pathways activated during the worms' response are similar to the pathways activated when more complex animals experience fear.
The ideal temperature for worms is between 55 and 77 degrees Fahrenheit. Adding worms to bedding: When bedding is ready for the worms place the worms on top. They will disappear in a short time in the bedding.
“Basically, if immature worms sense stress of any kind they can temporarily halt their normal growth for months and then restart it when the stress passes. This temporary freeze in the growth process is the dauer state,” said Dr. Hobert.
The worms are otherwise silent, even when the researchers tried to aggravate them. Normally, creatures making a noise like this use a hard structure at some point on their anatomy, like the snapping shrimp, which produces a loud noise by closing its claws rapidly.
Earthworms have such a high sensitivity to salt the overexposure can result in reduced growth and their sensitive skin being destroyed. All this is because the worms do not have control over their osmotic regulation.
But after a rain, the soil pores and the worm burrows fill with water. Oxygen diffuses about a thousand times slower through water than through air, she says. “The worms can't get enough oxygen when the soil is flooded, so they come to the surface to breathe.” Beats drowning.