Interested in learning more about fireflies? Here are a few fascinating facts you may not know.

Fireflies talk to each other with light.

Fireflies emit light mostly to attract mates, although they also communicate for other reasons as well, such as to defend territory and warn predators away. In some firefly species, only one sex lights up. In most, however, both sexes glow; often the male will fly, while females will wait in trees, shrubs and grasses to spot an attractive male. If she finds one, she'll signal it with a flash of her own.

Fireflies produce “cold light.”

Firefly lights are the most efficient lights in the world—100% of the energy is emitted as light. Compare that to an incandescent bulb, which emits 10% of its energy as light and the rest as heat, or a fluorescent bulb, which emits 90% of its energy as light. Because it produces no heat, scientists refer to firefly lights as “cold lights.”

In a firefly's tail, you'll find two chemicals: luciferase and luciferin. Luciferin is heat resistant, and it glows under the right conditions. Luciferase is an enzyme that triggers light emission. ATP, a chemical within the firefly's body, converts to energy and initiates the glow. All living things, not just fireflies, contain ATP.

Firefly eggs glow.

Adult fireflies aren't the only ones that glow. In some species, the larvae and even the eggs emit light. Firefly eggs have been observed to flash in response to stimulus such as gentle tapping or vibrations.

This is an image of a firefly larvae just emerging from the egg. Copyright © Terry Lynch

Fireflies eat other fireflies.

Fireflies are primarily carnivorous. Larvae usually eat snails and worms. Some species of fireflies feed on other fireflies—most notable is the genus photuris, which mimics female flashes of photinus, a closely related species, in order to attract and devour the males of that species. But adult fireflies have almost never been seen feeding on other species of bugs. Scientists aren't sure what they eat. They may feed on plant pollen and nectar, or they may eat nothing.

Fireflies have short lifespans.

An adult firefly lives only long enough to mate and lay eggs—so they may not need to eat during their adult life stage. The larvae usually live for approximately one to two years, from mating season to mating season, before becoming adults and giving birth to the next generation.

Fireflies imitate each other.

Female photuris aren't the only impostors among fireflies—the species is surprisingly devious when it comes to imitation. Sometimes male photuris imitate male photinus to attract females of their own species. She shows up looking for food, but instead he gets a mate.

Even more interesting, scientists believe some photinus males imitate photuris females giving off bad impressions of photinus male flashes, scaring off other photinus males and reducing competition.

Fireflies are found on almost every continent.

Fireflies love warm, humid areas. Because of this, they thrive in tropical regions as well as temperate zones—they come out in the summertime in these environments—on all continents except Antarctica. Fireflies thrive in forests, fields and marshes near lakes, rivers, ponds, streams and vernal pools. They need a moist environment to survive.

Some species of firefly larvae are generally aquatic—they even have gills—while others live almost entirely in trees.

Fireflies are medically and scientifically useful.

The two chemicals found in a firefly's tail, luciferase and luciferin, light up in the presence of ATP. Every animal has ATP in its cells in amounts that are more or less constant—or should be. In diseased cells, the amount of ATP may be abnormal. If the chemicals from fireflies are injected into diseased cells, they can detect changes in cells that can be used to study many diseases, from cancer to muscular dystrophy.

But that's not all they're used for. Electronic detectors built with these chemicals have been fitted into spacecraft to detect life in outer space, as well as food spoilage and bacterial contamination on earth.

Fireflies don't make tasty prey.

When attacked, fireflies shed drops of blood in a process known as “reflex bleeding.” The blood contains chemicals that taste bitter and can be poisonous to some animals. Because of this, many animals learn to avoid eating fireflies. Pet owners should never feed fireflies to lizards, snakes and other reptilian pets.

有兴趣学习更多关于萤火虫的知识吗？以下是一些你可能不知道的令人感兴趣的事实。

萤火虫用光交谈。

萤火虫发出光主要是为了吸引异性，尽管它们也为了其他原因交流，例如保卫领地和警告捕食者。在一些萤火虫物种中，只有一个性别点亮了。然而，在大多数情况下，两性都会发光；雄性通常会飞，而雌性则在树、灌木和草中等待发现一个有吸引力的雄性。如果她找到一个，她会用自己的闪光信号。

萤火虫产生“冷光”。

萤火虫灯在能量的world-100 %最有效的灯发出的光。把它与白炽灯泡相比较，白炽灯的能量是光的10%，剩下的是热，或者说是荧光灯泡，它能发光90%的能量。因为它不产生热量，科学家们把萤火虫的灯称为“冷光”。

在萤火虫的尾巴，你会发现两个化学品：荧光素酶和荧光素。Luciferin是耐热，它发出正确的条件下。Luciferase是一种触发光发射的酶。ATP是萤火虫体内的一种化学物质，转化为能量并启动辉光。所有生物，不仅仅是萤火虫，都含有ATP。

萤火虫蛋。

光是萤火虫并不是唯一的萤火虫。在一些物种中，幼虫甚至卵发出光。萤火虫卵已被观察到闪光，以回应刺激，如轻拍或振动。

萤火虫虫卵发光的例子

这是一个萤火虫幼虫刚刚从卵中出现的图像。版权©Terry Lynch

萤火虫吃掉其他萤火虫。

萤火虫主要是食肉动物。幼虫通常吃蜗牛和蠕虫。萤火虫捕食其他萤火虫最著名的一些物种是Photuris属，模仿Photinus女性闪烁，一个密切相关的物种，为了吸引并吞噬该物种的雄性。但几乎没有见过成虫捕食其他种类的昆虫。科学家们不确定他们吃了什么。它们可能以植物花粉和花蜜为食，或者它们什么也不吃。

萤火虫寿命短。

萤火虫生命周期图

一只成年的萤火虫只存活足够长的时间交配和产卵，所以它们可能不需要在成年期进食。幼虫通常从交配季节到交配季节生活大约一到两年，然后再成为成虫并产下一代。

萤火虫互相模仿。

女性福图利斯不是唯一的骗子在萤火虫的物种是惊人的狡猾的时候，仿。有时雄性Photuris模仿雄性Photinus吸引女性自己种的。她出来找食物，却找不到配偶。

更有趣的是，科学家认为，一些北美男性模仿女性的男性发出Photuris萤火闪烁的坏印象，吓跑其他北美男性和减少竞争。

几乎每一个大陆都有萤火虫。

萤火虫喜欢温暖潮湿的地区。正因为如此，它们在热带地区以及温带地区茁壮成长，它们在南极洲以外的所有大陆的夏季环境中都能生长出来。萤火虫生长在湖泊、河流、池塘、溪流和温泉池的森林、田野和沼泽中。他们需要一个潮湿的环境来生存。

有些种类的萤火虫通常是水生的，它们甚至有鳃，而其他的几乎完全生活在树上。

萤火虫在医学上和科学上都很有用。

在萤火虫的尾巴发现两化学品，荧光素酶和荧光素，照亮在ATP存在下。每一种动物的细胞中都有ATP，其数量或多或少是恒定的或应该是。在患病细胞中，ATP的数量可能是不正常的。如果萤火虫的化学物质被注射到患病的细胞中，它们就可以检测出细胞的变化，这些细胞可以用来研究许多疾病，从癌症到肌肉萎缩症。

但这并不是他们所用的。装有这些化学物质的电子探测器已安装到太空船中，以探测外层空间的生命，以及地球上的食物变质和细菌污染。

萤火虫不会成为美味的猎物。

当被攻击时，萤火虫会在一种叫做“反射性出血”的过程中滴下血液，血液中含有化学物质，这些物质苦味，对某些动物可能有毒。因此，许多动物学会了避免吃萤火虫。宠物主人不应该给蜥蜴、蛇和其他爬行动物宠物喂萤火虫。