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Why are slugs and slugs so slow? —Sarah, age 11, Wichita Falls, Texas
Wander through your backyard or walk along a stream and chances are you’ll see a snail – small, squishy creatures with shells on their backs.
Snails are found in water, be it in salty oceans, rivers or lakes. They are also on land: in forests, grasslands and even in your garden.
While exploring your garden or forest, you may also come across snails, which are slow-moving animals related to snails. They’re similar, too, except that snails don’t have a shell.
Not only can you find snails on sidewalks or on plants in the park, some of them are also in our oceans.
All told, there are an estimated 240,000 species of snails and snails living around the world. But no matter what continent they’re on or what ocean they’re in, there’s one thing they all have in common: they move slowly.
Here’s an example of how slow they are: The World Snail Race Championshipsheld in the UK, the fastest snails compete against each other in a “foot race”.
The fastest snail on record sped through the course at a blistering 0.06 miles per hour.
In other words, if you were that slow, it would take about three minutes to get a bite of food from your plate to your mouth.
Molluscs are everywhere
How come slugs and snails are not in a hurry?
As researchers who specialize in the study of plants and animalswe learned that the answer is more complicated than you might think.
Snails and slugs belong to a large group related animals known as molluscsincluding clams, oysters, squid and octopuses.
Within the mollusks, there are a smaller number of related animals called gastropods; this also applies to snails and snails.
Because they live in such different places, different gastropods have evolved to consume almost any type of food. Some species are herbivores – they eat living plants. Some are detritivores – they feed on dead or decomposing plants. Others are carnivores or scavengers – they eat other animals.
The reasons for slowness
Snails’ lack of speed can be attributed to at least three factors: how they move, what they eat, and what they eat.
First, while some animals fly, jump or slide, slugs and slugs move with the help of what biologists call the “ventral foot.” But the word “foot” can be confusing here. A snail or snail’s foot is nothing like a human foot.
Instead, it’s a band of muscle that runs along the underside of their bodies and is covered in sticky mucus. When this muscle is contracted, it ripples and sends small waves from the animal’s tail to its head. These waves compress the mucus on the underside of the foot into a slippery liquid, which allows the snail or snail to glide on the ground or climb plants.
It’s a unique way of moving and it forces slugs and slugs to go slowly because their speed is limited by the number of foot contractions and the amount of mucus they can make.
And snails and snails don’t have to rush to find their food anyway.
Many animals, especially predators, must move quickly to catch a meal; for example, a cheetah must be faster than a gazelle. But most slugs and snails eat plants, decaying matter or marine animals, like sponges, which are anchored in place. No one moves much, so dinner isn’t going anywhere – no rush.
Dealing with predators
Nor do slugs and slugs need to be fast to evade predators. They have developed other ways to avoid mice, birds and shrews and other enemies.
Usually snails retreat into their shells to hide until the predator passes.
Land snails hide in plain sight. Most are shades of gray, brown or brown and blend in well with their surroundings. Predators just don’t notice them. They also have an extra layer of protection. Land snails are covered in a sticky mucus, similar to the slime that lubricates their movement. But this version is so gooey that it can chew the mouths of predators and make chewing difficult. Not to mention that most predators probably wouldn’t like the slime very much.
Sea snails, on the other hand, are often easy to see because they are colorful. But these bright colors advertise to predators to stay away, as the snails are protected with foul-tasting toxins.
Treat slugs and slugs with respect
Snails and slugs, small as they are, make a big contribution to the health of their ecosystems.
By feeding on seeds and young plants, they can control which plants grow in an area. By eating decaying matter, they help recycle nutrients for growing plants to use. And despite their best efforts, slugs and snails often become food for other animals.
So the next time you see a slug or slug hanging from a plant, dawdling in your yard, or slithering across a concrete sidewalk, stop and observe. Think of its remarkable biology, the unique way it moves and looks, and the many ways it benefits the environment.
And then let them be. These little animals help keep our world going.
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