Chapter 21 Insects remember the spider's telegraph wire

Of the six garden spiders, only two usually rest in the center of their webs, the striped spider and the silky spider.Even if they are scorched by the scorching sun, they will never leave the net easily to rest in the shade for a while.As for the other spiders, they do not appear during the day.They have their own way of keeping work and rest in sync, and not far from their nets there is a hidden place made of rolled leaves and wire.They hide here during the day, quietly, letting themselves fall into deep thought. This sunny day, though dizzying for the spiders, is also the time when other insects are most active: the locusts dance more lively, and the dragonflies dance more merrily.So it is a good time for spiders to prey. Although the sticky web is the spider's residence at night, it is still a big trap during the day. If some careless and stupid insects touch the web, they will be stuck and hide elsewhere. Will the spider know it?Don't worry that the spider will miss the opportunity, as long as there is movement on the web, it will rush over like lightning.How does it know what's happening online?Let me explain.

It is the vibration of the web, not its own eyes, that lets it know there is prey on it.To demonstrate this, I placed a dead locust gently on a web containing several spiders, and placed it where they could see it.A few spiders were in the web, and a few were hiding in hiding places, but none of them seemed to know that there was prey in the web.Then I put the locusts in front of them, and they still didn't move.They seem to be blind and can't see anything.So I stirred the dead locust with a long blade of grass, and set it in motion, and at the same time set the net vibrating. The results proved that the striped spiders and silk spiders parked in the webs quickly rushed to the locusts; other spiders hidden in the leaves also rushed quickly, as if they usually catch live insects, and skillfully released silk to bind the dead locusts again. Bundle and wrap, without any doubt that you are wasting precious silk thread. From this experiment, it can be seen that when a spider comes out to attack its prey, it depends entirely on when the web vibrates.

If we look closely at the webs of those spiders which live by day, we see a thread running from the center of the web to the place where it hides, and the length of this thread is about twenty-two inches; but the webs of the horned spiders are different. , because they live in seclusion on tall trees, so its filaments are generally eight or nine feet long. This oblique line is also a bridge, relying on it, the spider can rush from the hermitage to the web, and then follow it back to the hermitage after finishing its work in the center of the web, but this is not the case. The full utility of this thread.If its function only lies in these, then the thread should lead from the top of the web to the spider's hiding place.Because this can reduce the slope and shorten the distance.

The reason why this thread is drawn from the center of the net is because the center is the starting point and connection point of all the spokes, and the vibration of each spoke has a direct impact on the center.A bug struggling in any part of the web transmits vibrations directly to the central thread.Therefore, the spider hides in a distant hiding place, and can get the news of the prey's capture from this thread.The oblique line is not only a bridge, but a signaling device, a telegraph wire. The young spiders were very lively, and none of them knew the art of connecting telegraph wires.Only the old spiders, when they sat silently meditating or dozed peacefully in their green tents, listened to the signals from the telegraph wires, and thus learned what was going on in the distance.

Waiting for a long time is hard work, in order to reduce the pressure of work and have a good rest.At the same time not letting up one bit of vigilance about what is happening on the web, the spider always rests its legs on the telegraph wire.Here's a true story to prove it. I once shot a horned spider that had made a web between two evergreens a yard apart.The silk screen shone brightly in the sun, and its owner hid in the house before dawn.It's easy to find where it lives if you follow the telegraph wires.It was a dome made of dead leaves and silk.Made so deep that the spider's body is almost entirely hidden inside, blocking the entrance with the back end body.

Its front body is buried in its abode, so of course it can't see what's going on on the Internet—even if it has a pair of keen eyes, it may not be able to see it, let alone it is actually half-blind!So in the sunny day, does it give up predation?Let's take another look. You see, one of its hind legs suddenly sticks out of the leaf house, and the top of the hind leg is connected to a silk thread, and that thread is the other end of the telegraph wire!I dare say that whoever has not seen this unique trick of a spider, that is, the gesture of placing its hand (that is, the end of its foot) on the telegraph receiver, will not know one of the most interesting displays of animal intelligence. example.Let the quarry appear on this web, let the dormant hunter feel the signal from the telegraph!I deliberately put a locust on the Internet - what next?Everything is as I expected, the vibration of the insect drives the vibration of the web, and the vibration of the web is transmitted to the feet of the waiting spider through the silk thread - "telegraph wire".The spider is content with its food, and I am more satisfied than it is: because I have learned what I want to learn.

There is one more point worth discussing.The spider's web is often moved by the wind, so can the telegraph wire not distinguish whether the vibration of the web comes from the approach of prey or the blowing of the wind?In fact, the spider, which closed its eyes and meditated in its dwelling, did not move when the wind caused the telegraph wires to shake, and seemed to dismiss the false signal.So another magical thing about this telegraph wire is that it is like a telephone, just like our human telephone, which can transmit various real voices.The spider attached a toe to the telephone wire, listened to the signals with its legs, and could distinguish between the signal of the prisoner's struggle and the false signal of the wind blowing.