Spiders are known as some of the most hardy creatures on the planet, seemingly being able to survive most things thrown at them.
Spiders are almost always seen hanging out in their webs waiting for food… but what if food never comes? How long can spiders go without eating?
The answer is quite surprising, and that spider you have trapped under a cup may live for longer than you think.
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How Long Can Spiders Live Without Food?
Spiders can live for between 1 month and 2 years without food, depending on the type of spider and conditions that it’s living in.
Typically, larger spiders can survive longer than smaller spiders, and pet spiders can survive longer than wild spiders.
In order to better understand how long a spider can live, it helps to know why exactly they’re able to go so long without food in the first place.
Why Can Spiders Live So Long Without Food?
First of, spiders are cold blooded, or exothermic creatures. In cold blooded animals, body size is a good indicator of their metabolism. So, a small spider would have a slower metabolism than a large ball python, for example.
This is especially true for spiders, as they have a metabolism that’s about 50% the speed of other creatures around their size.
Additionally, spiders are carnivorous, so they get a lot more energy from their food than an herbivore would.
Then, you need to look at the daily activities of most spiders. Many of them are sedentary ambush predators that rarely move throughout the day. This requires the use of very little energy.
Many spiders spin webs, which is a process that consumes a lot of energy, but many spiders simply eat their webs and use that protein to build a new one.
So, this combination of a very slow metabolism, calm and simple lifestyle, and low-effort hunting strategies allows spiders to live a very long time without eating any food.
Tarantulas Without Food: An Incredible Outlier
While small, common house spiders may live for about 2-4 months without food, tarantulas are able to live for much, much longer.
In fact, tarantula owners commonly report that their tarantulas haven’t eaten for 6 months to 2 years! This isn’t because of a lack of food, either — they just choose not to eat.
It’s difficult to say why exactly tarantulas have this strange behavior. Sometimes it’s because they’re undergoing a lengthy molt, and other times it’s because they’re “anxious”… But most of the time it’s just what they do.
Some types of tarantulas are actually known to go on very long hunger strikes, such as Grammostola rosea.
The tarantulas that go the longest without food tend to be more docile and inactive, so they fit the inactivity theory well.
Additionally, a tarantula’s lifespan is extremely long, demonstrating the effects of a sedentary lifestyle.
How Long Can They Live Without Water?
Like all living creatures, spiders need water to live. However, their relationship with water is much different from you and I, so their water requirements are also much different.
Spiders can technically live a very long time without drinking water. This is because while spiders drink water, they don’t do it very frequently.
Instead, spiders get their water through their food and through their environment. A spider in a humid environment with a healthy diet will almost never need to drink water.
However, this means that a spider typically can’t survive more than a few days in a warm, dry environment without food.