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City Spiders Are Bigger And More Fertile

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Normal spiders are creepy enough, but city spiders have them beat. According to new research, certain spider species will grow larger and produce more babies when they are in urban areas compared to their cousins in the countryside.

Not all insect or animal species are able to adapt to urban life. Some species will flee the city, while others will thrive in it. This is the case for some spider species that can adapt very well to urban life, to the point where they do better in cities than they do in their natural habitats.

To figure out just how much spiders benefit from living in urban areas, researchers took specimens that lived in urban, semi-urban and rural sites, and they’ve found that spiders living in an urbanized environment with less vegetation had larger tibias. A spider’s tibia can be used to estimate the overall body size of a spider, which is why researchers targeted it. When compared to rural spiders, the urban and semi-urban specimens had tibias that were 0.13 inches longer on average, which is a significant increase. The urban spiders also had significantly larger ovaries, which weighed up to 39% of their total body weight. This indicates that the urbanized spiders have a higher reproductive capacity.

So why are urban areas so beneficial for these spiders? We know intuitively that there are more insects in an open field than there are in a city, so it can’t be more abundant food sources. It is actually the heat. Spiders love heat, and cities are hotter than rural areas. Hard surfaces such as buildings, roads and concrete all retain heat, which raises the temperature and benefits the growth of these spiders. The temperature difference can be as much as 5.4 degrees Fahrenheit between a city and an open field, which is ideal for spiders.

While this might sound like a nightmare, it actually benefits city dwellers, because most of these spiders are not indoors, but outdoors where they keep mosquito populations as low as they get. Still, if you do live in a city, and you end up with an infestation, the spiders will be able to grow in number faster, so you will have to take care of an infestation as soon as you notice it. Contact us today if you have spiders in your home and they need to be removed quickly and effectively.