Qualified draft animals must have sufficient pulling strength, speed and continuous working time (endurance), so not all large mammals can become draft animals, and "grass and mud horses" are eliminated due to insufficient pulling strength and can only be used as lightweight pack livestock.

After evaluating the three indicators of pulling strength, speed and continuous working time, the protagonist feels that among insects, the best objects with the potential to become draft animals are the beetles. Among them, the protagonist's favorite ones are the spade armor and the unicorn fairy.

Stag beetles, also known as stag beetles, are the collective name for about 1,000 species of beetles in the family Lucanidae of the order Coleoptera.

Stag beetles are generally medium- to extra-large insects, with a body length of 70 to 129 mm, an oblong or oval body, and a rather oblate dorsal and ventral body. The body color is mostly tan, black-brown to black, or brownish-red, yellow-brown and other spots, some species have a metallic luster, and usually the body surface is not hairy.

The sexual dimorphism of stag beetles is very significant, with a large head, close to the size of the forechest, and an abnormally developed upper jaw, mostly antler-shaped. Males of the same species also differed significantly in size and complexity due to different levels of development. The lip base of the stag nail comes in a variety of forms, and the compound eye is usually not large. The elytra are well-developed and cover the back like natural armor, and 5 ventrals are visible on the abdomen.

The most characteristic feature of stag beetles is that the male has a well-developed palate, which resembles the horns of a stag deer. Many species have finer branches and teeth on their horns, and the horns are as long as their bodies, and the Sumatran giant stag beetle can even cut off human fingers.

The stag armor is an aggressive insect with its long palate as its weapon, and its whole body is covered with armor, like a heavily armed samurai.

Most stag beetles live around rotten wood, where the larvae feed on the rotten wood and the adults suck the sap or nectar. Adults are mostly active at night, and some species have phototaxis, but there are also daytime species.

The one-horned beetle, also known as the bifurfurcated rhinoceros beetle, is an insect of the genus Rhinoceros in the family Scarabidae, named because the male has a well-developed head horn and lives in the forest.

The body length of the adult is generally 30 to 50 mm (excluding the frontal horn), the body width is 20 to 30 mm, the body is oblong oval, the back of the body surface is smooth or slightly hairy, and the ventral surface is hairy.

The body color of the unicorn fairy varies greatly from dark red to reddish-brown to pure black, and sometimes the color of the cephalothorax and elytra of the same individual will also be different. The head is small, the compound eyes are dark reddish-brown, and the upper lip is an upturned flat spatula. Elytra shoulder warts and terminal warts are well developed.

The phenomenon of unicorn fairy dimorphism is also significant, males have well-developed frontal horns, 15-35 mm long, protruding forward, the end curved upwards and divided into four forks, smaller individuals may have only two prongs, and the center of the dorsal plate of the anterior thoracic plate protrudes forward with a prothorax dorsal horn, slightly curved downward, and the end is bifurcated. The female has only a small bulge at the top of the forehead, without the dorsal angle of the prothorax, and the dorsal plate of the thorax has a Y-shaped concave concave. Males have brighter backs and females have darker backs. Males have significantly longer forelegs than females.

The larvae rely on humus soil or humus formed by rotten wood under the forest to feed, so they have higher requirements for the originality of the forest, especially the C. glaciaceae, such as Quercus glauca. In addition, the larvae also live in decaying grass piles, wood chip piles in lumber mills, wood chip medium in mushroom farms.

In the human world, adult unicorns begin to emerge in early summer, are most common in June and July, and most die in September. Adults like to be active at temperatures above 20 °C, and rest in dark and humid environments such as leaf litter and soil during the day, and begin to be active at dusk, with phototaxis at the peak of activity in the first few hours of the night after sunset.

Adults feed on the sap from tree wounds or ripe fruits, and although they have chewing mouthparts, they are highly specialized in feeding methods, first cutting through the bark or skin of the fruit with a shovel-like upper lip, and then licking the sap or fruit with their brush-like tongue, which attracts other insects to feed together. If you don't eat enough food during the night, you can also continue to eat on your stomach during the day.

The males of the unicorn are aggressive and will fight with their foreheads for food and mating rights. The two combatants will first shake their foreheads up and down, contract their abdomen and make a "chirp-thump-" sound, and if neither side retreats, they will try to insert their foreheads under their opponent's body and lift them up. The side that is lifted is the loser, and generally only needs to be lifted once and immediately admit defeat and flee. Stag beetles also have similar mating competition behavior.

Adult unicorn worms often have a large number of mites attached to their body surface, but they are generally not life-threatening.

Stag beetles and unicorns have the characteristics of larger size and greater strength, coupled with their herbivorous nature, their aggression is also more aimed at competitors when mating, and they are usually more docile, and they are simply the "old cattle" in the insect world.

In the human world, the life span of stag beetles and unicorn fairies is not long, unicorn fairies can only survive for 1-3 months, and the life span of stag armor is generally half a year, and a few individuals can survive the winter and live for another season.

But in this world, the protagonist knows from the packets of information observed by other ants that these big men can live for years to ten years, even longer than many ants.

With enough lifespan, it is more economical and feasible to domesticate stag armor and unicorn fairy, after all, if draft animals need to spend a lot of time domesticating and can only be used for a few months, it is undoubtedly a waste of time, energy and materials.

At the same time, the protagonist also notices that this longevity phenomenon does not only appear in stag beetles and unicorns, but also that the large-headed ant race in which the protagonist lives, whether it is worker ants, soldier ants, male ants and queens, have a longer lifespan than their counterparts in the human world, and the queen and male ants can even live for more than ten years.

And through the Floating Leaf King, the protagonist knows that the lifespan of the paver ant is roughly the same.

However, the average lifespan of the newly accepted scythe ants is shorter, and their warriors generally only live for a few months to a year or two after breaking the pupa and become adults, and the queen ant can only live for three or four years.

However, this short lifespan does not mean that the lifespan of the scythe ant is inherently short, you know, most of the scythe warriors are killed in war or hunting, and almost none of them die. And a tribe of hunting sickle ants can only exist for an average of a few years, which happens to be close to the average lifespan of a queen ant or male. This means that if there is a peaceful environment, there is a lot of room for the lifespan of the hunting sickle ant to increase.

When the Divine Envoy King conquered the southern hills, in the tribe of the Hunter Sickle Ant that encountered the bark mantis, he captured and captured a cowardly old Hunting Scythe Ant male, and he lived for four or five years, and he still looked healthy, which was considered a high life expectancy among the Hunting Scythe Ants.