Giant mutant ants. Shrinking men. Science fiction is filled with all sorts of fantastic voyages into the impossible, and my favorite has to be matters of size. But here’s the thing: In the real world, the gigantic beasts that dazzle us in movies probably wouldn’t even be able to function, let alone stand up!
Let’s consider the giant mutant ant.
Ants, like all insects, are arthropods. They’re invertebrates with skeletons on their outsides, called exoskeletons. Yeah, gross.
Now, what happens if you use your embiggen ray to make one of your pet ants a giant? Due to the now-giant ant’s increased cross-sectional area, its legs (which are basically hollow tubes) won’t be able to support its newfound weight, and therefore it won’t be able to stand.
Pretty anticlimactic, right?
Of course, this really depends on just how big you intend to make said ant. There’s evidence that ants the size of hummingbirds once existed. If you’re aiming for Them!-sized, it may be possible to a point (we’ll get there). But if you’re wanting one supremely gigantic ant big enough to rampage a whole city Godzilla style, that’s going to cause some problems.
You can’t simply “blow up” an ant and expect it to be the same only bigger. After all, ants are the size they are because that size fits their environment (gravity included).
Consider how as animals grow larger, their bones, and especially their legs, grow larger as well. Insects have small thin legs because they don’t need as much support, while elephants have large tree stump legs. Because they’re fashionable but also it’s the only way they can get around. Because they’re elephants. And because the square-cube law exists.
The square-cube law was described by Galileo Galilei in his classic 1638 hit The Two Sciences, and is a principle that basically says that while a shape grows proportionally in size, its surface area and volume will change at different rates. Its volume will increase by the cube of its scale factor, while its surface area will increase by the square of that same scale factor.
So let’s say you double the size of an object or person or ant. That’s a factor of 2. The object’s surface area will increase by a factor of 4, or the square of the scale factor (2 x 2). Meanwhile, the volume will increase by the cube, meaning the object will increase by a factor of 8 (2 x 2 x 2). It’s suddenly having a much harder time keeping itself up!
In the case of the giant giant ant, if it grew proportionally, you’d probably end up with a bumbling gob of immobile ant parts just kind of squirming around. It just wouldn’t be a good time for anyone.
Somebody Get Some Towels
Now wait a second. That wouldn’t be your giant mutant monster ant’s only problem. No, you and your embiggen ray have doomed it to a very short (and potentially messy) life, indeed!
This is because ants don’t have a closed circulatory system like we do; it’s open, so their blood just kind of flows freely through an internal cavity. Yeah, gross.
This works well at their small size, because there’s not a lot of area to cover, and it can flow a lot quicker from one part to the next. Their physical movements aid this process, as well.
But turn them into giants and the entire equation changes — suddenly that blood can’t so easily get where it needs to be. As soon as your pet ant becomes gigantic, it will probably be dying.
The same problem occurs with breathing. Yes, ants breathe oxygen, only they do it through tiny holes throughout their bodies called tracheae. Oxygen enters these holes and is transported to cells. The problem with growing larger is that your giant ant is going to need more oxygen, and that means more and larger tracheae, and that means more tubes and less biomass. And that means…well, it’s a whole thing.
In Session 5 of his article “The Biology of B-Movie Monsters,” Michael C. LaBarbera tackles the enlarged ants of Them!. Long story short, if their respiratory and circulatory demands were sufficient at their mutated giant size, they might be able to walk, under one condition – their joints would need to be made of diamond.
The original problem with their legs is still in play, though – as essentially hollow tubes, they’d be vulnerable to local buckling. A good hit with a brick would be enough to cause a kink in their leg, and ruin their chances at walking and therefore a happy ant life.
This is good news for us, but not for your giant immobilized pet ant. You monster.
