Even in an age where you can fly from LA to London in comfort, private planes are readily available, and we’ve gone beyond the Wild Blue Yonder and lifted off into the Final Frontier, the question of flight remains as elusive and alluring as ever. Since at least Leonardo da Vinci’s design for an Air Screw, we’ve understood the possibilities of manipulating air to create lift, and with the Wright Brothers at Kitty Hawk, we made that happen, and have been improving on our designs ever since.
Birds, bats, and other flying animals, however, have had millions of years of evolution to “improve their designs,” and can still fly easier and more naturally than we ever can or will. Even so, while we often think of birds as mavens of the sky who fill the pages of poetry and paintings with beauty and grace, bats aren’t given the same treatment. Part of that has to do with the fact that it’s a bit harder to romanticize insect-eating blood-sucking cave dwellers, but part of that is also due to the comparatively herky-jerky way in which bats fly.
That brings us to the big question – can bats even take off from the ground? How do they take off and land, especially when they sleep upside down?
Bats vs. Birds in Flight
Even if you have seen a bat in flight, you might not have seen one on the ground. Bats sleep upside down, and then they take off with no in between. This means that unlike birds, they do not take off from the ground. Instead, bats take off from an upside down stance, dropping down like a dive bomber before flapping their way back up.
It may look a lot less elegant and graceful than birds’ ability to take off from the ground, but there’s no doubt that it’s effective. As we’ll see below, there are many reasons why bats don’t take off from the ground, but first, let’s take a better look at how their dive bomber style of flying works.
Bats typically need to drop down about two or three feet before they turn upwards and fly. That being said, bats tend to be much lighter than birds, even down to their bones. Just as differently-constructed aircraft have different flight capabilities, the varying builds of birds and bats impacts their flight styles. For one thing, bats’ wings are a lot thinner than most birds’ wings. While birds’ wings may be thin, they are positively thick compared to the thin webbing of a bat’s wing, which forms a patagium. This thin membrane, unlike the feathered wings of birds, is basically like stretching out skin and catching wind beneath it. It allows bats to generate the lift they need to fly. On the flip side, bats tend to have more bones in their wings than do birds, which boast a few hollow bones that enable them to remain aerodynamic enough to fly. By contrast, bats’ bonier wings have the potential to give them a greater degree of control than birds.
That said, birds’ wing construction is built for taking off from the ground, as are their legs. By contrast, bats’ legs are not built to support their weight well while on the ground, let alone allow them to push off and take flight in the same way birds do. Instead, their method of flight relies much more on dropping down from an elevated space and then flapping and gliding with those membrane-like, bony wings.
Bats wings are not constructed to produce enough lift to get them off the ground on their own, and unlike birds, they cannot give them a running start, either.
Bats and the Ground
As a result of their skinnier construction, bats are far clumsier on the ground than birds. In fact, only a few bats, such as the burrowing bat and vampire bat, are noted for spending time on the ground with any regularity, with the latter having thicker legs than the average bat. In fact, not only can vampire bats waddle around on the ground, but they can even sprint about your feet as well. This adds to the fright factor surrounding vampire bats since, contrary to myth, they don’t usually “suck your blood” from your neck Dracula-style, but rather go for your big toe. This is made a bit easier by the fact they can waddle along on the ground better than other bats.
A couple of other bats buck this trend too, including the lesser short-tailed bat in New Zealand which, while an adept flyer, can also crawl along to catch its prey on the ground. Its diet reflects that fact, as it eats a lot of plants, as opposed to bats who rely solely on plucking insects out of midair or hopping from spot to spot to eat.
That said, overall, bats do not fly by touching the ground. Let’s follow that up by saying that not only do bats hardly ever touch the ground, but if you do find them on the ground, you might want to leave them alone, because they could be dangerous.
Bats cannot take off from the ground for all of the reasons mentioned above. That means that, if you find them on the ground, they are almost certainly not there of their own choosing or volition. As a result, aside from a bout of clumsiness, the most likely explanation for why a bat might be on the ground is that the bat is either injured or sick, neither of which bodes well for you.
If the bat is sick, you definitely do not want to go anywhere near it. Bats are noted spreaders of diseases ranging from rabies to SARS. This is always a danger with bats, but if you find one or more on the ground, that’s a good indication that they are not well, which may indicate a greater possibility that they have a disease such as these or others which you absolutely do not want to contract.
Even in the “better” scenario, that is, that the bat is injured, you do not want to go anywhere near them. While it is understandable why you might want to help the bat, and that compassion is commendable, bats don’t understand that. A desperate animal is a dangerous animal, and a wounded bat seeing you approach could feel threatened and may thus be even more likely to scratch and bite you – which in turn can make contracting a disease from them even more likely. While contracting rabies from bats is rare nowadays given the precautions put in place via the CDC and animal control agencies, among the extremely rare cases of this that still occur in the US, a common cause is people picking up sick bats.
In short, bats don’t fly “Free as a Bird” but instead go “Free Falling” from a heightened perch and then flap their way to their next meal, all without taking off from or landing on the ground. While there are a couple of exceptions to this rule, on the whole, bats spend hardly any time on the ground, are wobbly and awkward in the rare occasion that they find themselves there, cannot push off and fly from the ground the same as birds and, if you do happen to find a grounded bat, it’s probably a sign you should stay away.