Spiders are truly fascinating creatures that live almost everywhere on the planet and are able to adapt to a lot of harsh environments. But spiders are probably most well known for creating intricate webs to catch their prey with but how exactly do they make their webs?
As a whole, spiders make their webs with the help of a special organ called the silk gland where the spider silk is produced and stored in liquid form. The liquid silk hardens and gets spun to a silk thread in another organ called the spinnerets on the spider´s abdomen.
Spider silk is made out of connected and unconnected protein chains. Spider silk with connected protein chains is stronger and more rigid while silk with unconnected protein chains is more flexible.
When building a web the spider will use both kinds of silk to ensure that the web is strong and flexible at the same time.
Depending on the species of spider the amount of silk glands and spinnerets is different but most spiders have three spinnerets (can have between two and four) and three silk glands (can have between two and seven).
Each silk gland can produce a different kind of silk but more on that later.
Every spider can make webbing but not every spider will use a web to hunt prey. Tarantulas, for example, only use their webs around their hiding spot to alarm them of potential predators or prey that is nearby.
How do Spiders Produce Silk?
Spiders can produce a wide variety of different silk types depending on what kind of silk gland is used to produce the silk. But how does this actually work and how is the spider able to create silk in the first place?
As a whole, spiders produce silk in an organ called silk glands. There are seven different types of silk glands that each produce a different type of silk. A spider can have between 2 and 7 of these silk glands. There is sticky silk, silk for protecting eggs, silk for storing captured prey, and more.
The silk is produced and stored in liquid form inside the silk glands. When the spider needs to spin a web then the liquid is being transported to the spinnerets where the liquid solidifies into the silk and is excreted out of the abdomen of the spider.
Each gland creates a different kind of silk but not every spider species has seven glands. Most only have three to four.
In total there are seven different types of silk that are all produced in a different type of silk gland.
Here is a table that shows you the different silk glands and what kind of silk they can produce.
|Type of Silk Gland||Kind of Silk the Gland Produces|
|Ampullate Major||Dragline Silk. This type of silk is used for the outer part of the web. It is also used for ballooning and when the spider is descending from somewhere.|
|Ampullate Minor||This type of silk is only used temporarily for scaffolding during the construction of a web.|
|Tubuliform||This type of silk is used to protect the egg sacs of the spider.|
|Flagelliform||This type of silk is sticky and is used for some parts of the web to capture prey.|
|Aggregate||This type of silk is used on intersections where two strands of silk on a web intersect. It is basically a glue to hold these silk strands together.|
|Piriform||This type of glue is also used to bond different types of silk together.|
|Aciniform||This type of glue is used to wrap freshly captured prey and to store it for later consumption.|
Where Does Spider Webbing Come Out Of?
There is a common misconception that spiders poop out the spider silk and some children even believe that spider webbing is just spider poop which is false. But where does the webbing come out of then?
As a whole, the webbing from a spider comes out of its spinnerets that are located under the anus of the spider. Spiders can have between two and four spinnerets but most spiders have three. The spinnerets do not produce the silk they only excrete it the silk glads produce the silk inside the spider’s body.
The spinnerets and the anus of the spider are very close together which probably leads to the common misconception that spiders poop out webbing.
Can Spiders Run Out of Webbing?
I personally found this question very interesting and it is not as easy to answer as you might think. So can a spider run out of webbing?
As a whole, spiders can run out of webbing but it is rare. The silk for the webbing is stored in liquid form in the silk glands (an organ of the spider that produces silk). These silk glands only have a limited capacity and if they are empty then the spider has to reproduce some silk which can take a while.
Spiders often eat webbing that they don´t need anymore to recoup some of the proteins so that they can create more webbing.
Most spiders are very careful with their use of webbing because they know that it is important for their survival. So they only use as much silk as they need and rarely run out of silk. But it can happen and if it does the spider will often hide and wait out until the silk glands are full enough to create more webbing.
Lisa is one of the two founders of Animal-Knowledge. She has been very interested in animals and insects from a very young age and has owned different kinds of pets such as snails, ants, fish, turtles, mice, rats, hamsters, rabbits, a dog, … you get the idea 🙂