Going bats

At dusk each night, I watch the flying foxes, the local fruit bats, making their way to wherever they go to feed. They roost somewhere to the west, and dine somewhere to the east, and as I live on a ridge, they fly past at about window level..

Some bats are so exceedingly ugly, that it can be little surprise that they are regarded with horror.

These are the small insect-eating flying mammals which make a specialty out of using echolocation to find their dinner, in the form of flying insects.

We cannot hear the noises these bats make to find their food, but some moths can hear them, and they have evolved to drop, very fast, when they hear a bat's call.

We speak of people being as blind as a bat, but in reality, bats see quite well — they just don't need vision, because they can 'see' with sound, but there is just one problem: how can a bat hear a faint echo at the same time that it is shouting?

The answer, it seems, is that they change their pitch, and those incredibly ugly faces of theirs are part of their hearing apparatus, channelling back the echoes, and distinguishing the pitch of the echo from that now being emitted.

There are quite a few other types of bat as well, though some of the terms seem to have evolved from other words. The animal called an evening bat is aften-bakka in Danish, while in Middle English, it was bakke, although 'flittermouse', a close parallel to the German fledermaus, is not unknown, reminding us that the bat looks very like a flying mouse.

Fruit bats are larger and zoologists call them the Megachiroptera. These bats do not use echo-location because fruit do not dodge out of the way, and according to some people, this group may have evolved separately from the small insect-eating bats, the Microchiroptera. Then again, maybe they all come from a common source, and evolved different habits. Last I heard, the evidence seemed to favour the idea that the bats evolved once, and then split into two groups.

There are real vampire bats in South America, small beasts with razor-sharp teeth which scrape at the skin of their victims, usually near a heel, and use an anticoagulant to keep the blood flowing as they slowly drink their fill. These are specialised forms of the insect-eating bats, and so they retain the ugly faces their ancestors needed for echo-location of insects.

It seems that the legend of the vampire came from Europe, and the link with bats is possibly related to bats as a source of rabies infection, as we will see shortly. In this, the South American vampire bats are just a neat coincidence, it seems.

A brickbat is entirely different. While we use the term mainly in a figurative sense, a brickbat is a piece of brick, less than half of the brick, with one end complete, and commonly used as a missile to hurl at an enemy. Its derivation is unknown, so perhaps it came from a piece of thrown brick, turning and appearing to flitter like a bat.

More likely, though, it came from the other main sense of 'bat' which means to strike or hit, a meaning which we see in a cricket bat, a baseball bat, or in terms like battery and battering ram. In that sense, a brickbat would be just a piece of brick used for hitting or striking — or perhaps a piece of brick that was broken away to finish a course of bricks, for that matter.

The batter that we put on something to be fried is apparently related to the hitting sense of 'bat', because part of the preparation involves beating the batter to mix it. The word 'battle', however, is a bit of a puzzle, and may not have come from the same root, or if it did, it came first through vulgar Latin, where it was battalia, and French, where it was bataille — and our 'battalion' also comes from this source.

Even 'cotton batting' comes from the fact that raw cotton has to be beaten by hand while it is being cleaned. When people started putting cannon together to batter the enemy walls in a siege, these were called a battery, and it seems we have Benjamin Franklin to thank for applying this name to a set of crude capacitors called Leyden jars, to make the first battery of the electric kind. And as usual, the work of Ben Franklin would take some beating.