This as-told-to essay is based on a conversation with Sara Goodacre, a professor of evolutionary biology who studies how spider silk can be used in medicine and engineering. It has been edited for length and clarity.

You should always question a spider scare story.

Recently, I read about a man who went on holiday and said a spider had laid eggs in his toe.

The man clearly had a serious problem with his toe, but spiders have never been known to lay eggs inside a human body, and the wound responded to antibiotics, which do nothing against spider venom. Biologically, it didn't make sense.

What annoys me is how many people are misled by such spider stories in the news.

We shouldn't be devoting any of our energy to fearing spiders.

Some very rare spiders can cause harm to humans, but, as I tell my children, spiders are far less likely to hurt you than cars or people.

But if you are scared of spiders, here's what you should know.

One misconception is that all spider venom causes harm to humans.

Some spiders are indeed venomous to humans, and you should make yourself aware of any spiders that could hurt you in your area — for instance, in the US you want to know how to spot a brown recluse and what to do in the rare case of an encounter.

But the overwhelming majority of spiders evolved to use their venom on insects. It simply doesn't work on humans.

Secondly, when a big spider comes into your house, it's not out to get you, it's a teenage male spider looking for a female.

You're better off feeling a bit sorry for him. This gangly youngster can't sprint very far and is terrified of your shadow, which it probably thinks is a bird coming to eat it. If it darts your way, it is not following you — it's just trying to stay away.

If you see a spider in your bathroom, you're better off just leaving it alone.

It doesn't want to use energy to escape from you, so unless you scare it, it's unlikely to fall on your head. It will just sit there until night when it will go eat the mosquitoes on your window sill.

I always suggest that people name the spider under their sofa. We always used to call ours Christopher. It's really hard to squash a Christopher.

The idea that you swallow a certain number of spiders every night is also an urban myth.

Yes, spiders walk around at night, but why would they deliberately venture into a weird, warm, humid mouth?

A few probably do get eaten by humans from time to time, just as people will sometimes swallow a passing fly, but it's the exception rather than the norm.

Lastly, spiders don't seem to harm that many people globally, and there are antivenoms for dangerous spiders such as the funnel-web spider or the black widow spider, which greatly reduces the risk of dying after a bite.

Next time you see a spider, ask yourself if the injury could have been caused by a cut infected by microbes instead and check your facts with a local reputable society of arachnologists. We're not afraid to say it exactly as it is.