These days, nothing much that happens in Yishun should come as a surprise to its residents.

An exception, perhaps, could be made for the appearance of several huge, fat caterpillars on the trunk of a tree on Yishun Ring Road — a sight one Christopher Yap could not possibly bypass and ignore:

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These velvety green, spiny crawlies are Atlas caterpillars, and look to be the length of a person's hand, with the girth of at least two fingers placed side-by-side:

Now if you recall what you learned in primary school science, caterpillars eventually turn into pupae, and then emerge from their shells as moths or butterflies.

The same happens here with the Atlas caterpillar. Here's what their pupa looks like:

And you'll probably be a bit less creeped out by them when you see what they look like when they emerge:

You might not be able to see their size here, but Atlas moths are among the largest in the world. Trust us — they're huge.

Check out the size of a young Atlas moth resting on a human hand, for instance:

Now, for a moment, it might seem entirely possible that these caterpillars are a harbinger of the imminent arrival of Mothra, the Godzilla-nemesis:

Because where else in Singapore would desperately need her powers to rescue it from the depths of "murderer and siao lang", right?

Time for some cool animal trivia:

Atlas moths are found only in Southeast Asia and are common in Singapore.

Interestingly, and perhaps a bit sadly, an adult Atlas moth does not have a mouth, living off fat reserves built up from when it was a caterpillar.

They probably tell one another these things in advance so the caterpillars know to eat as much as they possibly can (leaving even the tree they are pictured on rather bald), while they can, which is why they can grow up to 11cm in length.

Here's another thing that probably results from not having mouths — adult Atlas Moths only live for about two weeks, with their chief activities being mating and reproducing.

But before you dismiss these guys as useless, moths and caterpillars in general do have ecological functions — they help pollinate flowers, for instance (Primary school science again, hoo yeah!) and also indicate the quality of the environment they appear in.

So if you see and get irked by a number of these fat, juicy-looking green crawlies, just remind yourself what they'll look like in, hmm, a month or so.

If you're interested, you can check out their life cycle, complete with photos and detailed observations, on this local butterfly blog here and here.

If you love food, you'll be glad to know that Nasi Lemak may still exist in 2185

Apparently, this is what the government pictures Singapore to look like in 2185

Top photo by Facebook user Christopher Yap Hon Weng

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