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The night: The creatures to avoid in the dark

28 November 2013

Why would an animal evolve to be nocturnal? Why seek out a colder time during which one of the most crucial senses is rendered useless? The answer is that there are hidden benefits to hiding in the dark. Here are some of the strangest adaptations that allow animals to thrive in an unfamiliar temporal niche. Sally Adee and Jessica Hamzelou

Read more:The night: Things that go bump…

Scorpion

Like terrifying glow-in-the-dark toys, these animals luminesce at night, thanks to a cuticle that absorbs ultraviolet light reflected from the moon and emits a greenish-blue glow. Their luminescence may be part of a warning system that lets them know when the moonlight is so bright they risk being seen by other predators. It would be good to stay out of the way of those predators, since many of them are other scorpions: a scorpion's diet is 40 per cent scorpion. The glow may also attract another of the scorpion's favourite snacks, the moth.

(Image: Fabio Pupin/FLPA)

Honey badger

If the darkness is full of scary creatures, one solution would be to become the scariest creature in the darkness. The honey badger's aggression is legendary: it has been known to bite the heads off snakes and munch on scorpions. For this animal, everything is on the menu: they've been known to dine on beetles, lizards, birds, leguans, crocodiles and 3-metre-long pythons, not to mention the highly venomous black mamba snake. It's often said to have the habit of lunging for the genitals, but that may be a reflection of its fearsome reputation rather than an actual fact.

(Image: Laurent Geslin/naturepl.com)

Octodon

Some of the earliest nocturnal animals were small mammals known as proto-rodents. By occupying the darkness – the ability to generate their own heat meant they did not need to bask in the sun – it is thought that mammals could compete more successfully with diurnal dinosaurs. Today, this early legacy of nocturnal behaviour endures in night-dwelling rodents like rats, hamsters and the extravagantly named octodon, which sounds like it should be a dinosaur but is actually a nondescript mouse-like creature.

(Image: Rex Features)

Gila monster

One major advantage to being nocturnal is that in tropical and arid regions, it allows animals to prevent overheating and water loss. During the day, the Gila monster – a huge venomous lizard – stays in its burrow to avoid the extreme heat of the Mexican and the US deserts where it lives. Hunting at night, it flicks its forked tongue to pick up scents in the air and other information about its surroundings.

(Image: Joel Sartore/Getty)

Dung beetle

How do African dung beetles know where to roll their dung balls on dark nights? The nocturnal bugs appear to have evolved to use celestial cues. Researchers in Sweden and South Africa found that the beetles orient themselves by the patterns of the Milky Way in the sky, allowing them to transport their dung balls in straight paths and avoid "the intense competition at the dung pile". They're far from the only insects to use celestial cues to orient themselves. The compound eyes of most nocturnal insects are much more sensitive to light than those of their day-waking relations.

(Image: Mark Moffett/Minden Pictures)

Vampire bat

These archetypal creatures of the night feed on blood. To find prey in the dark, they listen out for the characteristic breathing of a sleeping animal. They then use unusual heat sensors on their nose to find prime flesh into which to sink their fangs. These thin, pointy incisors lend the bats their name, and are so sharp that the victim seldom notices the bite.

(Image: Samuel Betkowski/Getty)

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