It’s a great question – but there’s no simple answer. Some types of worms appear to have structures that resemble antennae and of the estimated 8,000 species of worms on earth, so far only 3,500 have been studied to the degree where they can be classified.
It is therefore likely that some other species will be found to have antenna or structures closely resembling them.
A recent discovery in Texas, for example, helped solve the question about how some worms were found to detect the earth’s magnetic field. So, do worms have antenna?
Yes, earthworms do have antennae. A worm takes great care in its survival and needs the antennae for it. Although it does not have lungs, hairs, limbs, etc, it does have a head (on its front half), a brain, more than one sensor, a mouth, cells that make up its body, and of course, antennae.
Do Annelid Worms Have Antennae?
Yes, they can. In fact, annelids are very sensitive creatures.
Annelid worms are those with segmented bodies. They have no hard skeleton or legs. Their bodies are distinguishable by their outer appearance of segments joined together in a series of rings.
These can stretch and contract to aid movement. Annelid worms include the common earthworm, for example.
Annelids are stimulated by and react to light, chemicals, temperature differences and moisture.
Velvet worms, too, have antennae. They are positioned in front of two eye-like structures. The eyes have very simple lenses which detect differences in light.
Velvet worms also have legs tipped with claws – the legs are found along the length of their body. The claws are useful to dig, make tunnels and deal with prey.
Velvet worms are in a special phylum known as ‘Onychophora’ which actually means bearer of claws.
Do Worms Have a Sense of Direction?
Weirdly enough, yes – the humble worm does seem to know where it’s going.
An exciting discovery was made in Texas in 2015. On June 18th that year, it was reported by Sarah Laskow, in the publication ‘Atlas Obscura’.
During this study, worms were examined with regard to how they used their sense of direction. More importantly, the team wanted to know about what gives worms them a sense of direction and how they were stimulated.
Experiments revealed they have neurons that help them orientate themselves. More importantly, these worms have the ability to detect and respond to the earth’s magnetic field.
The worms have a minuscule antenna shaped receptor, which facilitates this extraordinary sense.
The experiments above included placing worms in a jar of gel. Observers could see that when the worms were not hungry, they moved up through the gel. When they were hungry, they moved down.
What Else do Worms Use Their Antenna For?
They have been found to use the antennae to detect the presence of other animals that could present a threat to them (such as birds, moles, etc) and thus wiggle in opposite directions from the many organisms that could harm them.
It is known that when threatened, some tiny worms create narrow burrows underground. Many have bristles on their skin which they use to cling to soil and/or coil up, whilst trying to avoid being plucked up by predators. Some even have the ability to camouflage themselves.
It is felt that moving away from light sources, rather than towards light, gives the worms an advantage over some predators who require visual sight of the worms.
This sense of direction, usually up and down manoeuvres, are important for feeding as well as to survive certain predators.
Also, having a sense of direction is useful for worms to find the best places to lay eggs. In bitterly cold weather they may burrow deeper to avoid freezing surfaces – and in torrential rain, worms can often be observed actively moving.
In extremely hot sunny weather, they tend to burrow down to avoid ultraviolet light which can quickly kill them.
They also must sustain a moist covering on the outside of their bodies. If they become dry on the outside, they can’t ingest air to extract oxygen or dispel carbon dioxide.
So, in hot weather, worms seek moisture and cooler spots to make life easier. The antennae really do help in all these regards.
Summary
Although simple in shape and often quite small, worms have extremely well-developed sensory abilities. Once thought to be very simple life forms, scientists increasingly discover facts about worms that were once thought improbable.
We now know that earthworms react positively to stimulation. They deliberately seek to avoid problems or search for food and moisture or a change of temperature.
Where researchers have discovered antennas, they appear to be valuable to enhance the abilities of a worm’s body. Optimising directional options can actually lengthen or enhance the life of earthworms, too.
As technology advances, we will undoubtedly gain a better understanding of animal instincts and responses. We may also learn new things from the numerous worms as yet, unresearched. Could their antennae be hiding other secrets?
We now know better than ever before that worms, although very different from humans, share certain aspects that we may never have considered.
A worm actually takes great care in its survival. Although it does not have lungs as we do, nor hairs, it does have a brain, sensors, and various working organs – plus, of course, antennae.
Their role in the world is also far more important than we may even still fully comprehend. It is important to understand that without each and every earthworm and worm in the soil, other animals species, including our own, would not be able to live the way that we do.
Therefore, we need those antennae to keep things moving.
Thanks to the little earthworm eating the bacteria and the molecules from the decaying matter on the surface and within the soil (such as deceased organisms, plant roots, organic food scraps, algae, etc), the dead matter would then not be transformed into nutrient for the same soil that feeds all live animals and plants in the world.
Thankfully, then, worms seem to have a handle on things – with their own built-in GPS.
