Insectoids are incredibly diverse in their physical forms. They are commonly purple in color, with shades of either white, blue, or red. They have wings, mandibles, or “pinchers,” and either antenna or horns. Although most varieties have two eyes, some have six or more. Similarly, while many have two arms, four or more arms is not uncommon. Biologically distinct subgroups of Insectoids can be found in a single hive; produced by a single Insectoid queen.

It is almost as if his knees bend backward with each step and his jacket conceals several extra limbs. You notice, too, the odd, elongated shape of his head and his bulbous, protruding eyes. - Tome of Encounters (RPA-ADV3) 

Insectoids are natural diggers, creating elaborate tunnels and using a variety of methods to burrow into both earth and rock.

At least some Insectoids are capable of spitting “globs of acidic ichor” at enemies (RPA-BC: Brawler).

• Drone
• Laz'arax
• Urzon
• Verash
• Xanith
  • A fortune-telling oracle. (GS-ADV1)

After siding with the Dragul Alliance in the Great War, Insectoids established their own city-state north of the Abandoned Lands.

At Kulbak Prison, Insectoids were organized into a prison gang called Hagron's Hardbacks, known for their repeated escape attempts. Like many of the other Dragul prisoners there, the Insectoids longed for Khathandor's return, believing in prophecies that the dead Kobold general would rise from the grave to restore the Dragul to their former glory.

Traditionally, Insectoids are organized into tightly controlled, matriarchal communities. The hive is populated by eggs from a single queen. Some Insectoids, either by choice or necessity, live outside the structure of the hive, rejecting monarchy for either independence or more cooperative forms of self-governance. Most Insectoids, however, are more comfortable living in groups, regardless of the political structure of their societies.

Those which have been expelled by the hive - referred to as Mal'kanor - are known to be killed by the majority brood;

The swarm tears the injured Insectoid apart, carrying his remains back to their hive. - The Hive (GS-ADV3)

They may be labeled as such as early as their birth;

“When one of the eggs is rejected by the queen of the hive, they are usually eaten, but those that hatch are branded with an ‘X.’ They’re known as the Mal'kanor (MAL-ka-nor). Abandoned by the hive, they have nowhere else to turn.” - Eregrun, The Hive (GS-ADV3)

Even non-queens are capable of laying eggs, but Insectoids can be highly selective about which eggs are allowed to develop and ultimately hatch.

In dire situations, Insectoids have also been known to feast on their own eggs.

A few Insectoid prisoners sit together on the ground, their arms and legs intermeshed. The Insectoid at the center of this tangle of arms and legs has its mandibles latched onto a perfectly round yellow ball. She tightens her grip, cracking the ball in half and swallowing it whole. As she reaches for a second ball, it becomes clear that these are not some strange, unfamiliar fruit but rather Insectoid eggs upon which she is feasting. - Tome of Encounters (RPA-ADV5)

The other Dragul sometimes find the habits and practices of Insectoids to be strange, if not downright unnerving. In the interest of maintaining their alliance, they generally try to respect those differences.

“Better not to think about it. Insectoids are not Goblins. They have their own ways, and we must respect them.” - Gundur, Tome of Encounters (RPA-ADV5).

Insectoids view the world through the eye of a combined collective, motivated by the greater good of their people over any individual's need, want, or desire;

“The Insectoids don’t think like individuals. To them, a single death is inconsequential. What matters is the overall health of the hive. Some call that evil, but it’s just a different way of looking at the world.“ - Gulpax, The Hive (GS-ADV3)

Insectoids leave their dead to decompose naturally;

There are Insectoid bodies stacked from floor-to-ceiling, the corpses of laborers who did not survive the harsh working conditions of the mines. Insectoid bodies harden and turn brittle after death, producing a nauseatingly sweet smell.
…
“It is indeed a horrible sight, but it is consistent with the customs of Insectoids. They do not believe in burying their dead.” - Alpha-Zero, The Hive (GS-ADV3)

Elves and Insectoids do not tend to get along, which makes the presence of two of their respective gods next to one another in the Sacred Caverns of the Insectoid Hive quite unexpected;

Rax’akhan (RAX-a-khan), the Insectoid god of the harvest stands next to Kehstore, the Elvish god of mischief and disorder. It is strange to see an Elvish god worshiped in an Insectoid hive. Historically, Insectoids and Elves have not always seen eye to eye. - The Hive (GS-ADV3)

An Insectoid sentry patrols the path to the Dragul Outpost at Blacklake:

• Sneak past to continue on your mission:
  • Succeed, and the Insectoid never knows you were here.
  • Fail, and he will raise an alarm to alert his comrades.
• Take out the Insectoid patrol to ensure he will not follow you:
  • Succeed, and you effectively knock the Insectoid out.
  • Fail, and he will raise an alarm to alert his comrades.

You run into an escaped Insectoid prison of Kulbak in Undercity:

• You slay him in the event that he has been afflicted with vampirism.
• He escapes you and darts into the darkness.
• You let him pass and win favor with the Dragul.

A group of Insectoids are passed in Kulbak Prison eating their eggs when one rolls in front of you:

• You keep the egg for yourself, leading to an altercation:
  • You stave off the Insectoids long enough that the guards intervene to break up the fight.
  • The Insectoids reclaim and eat their egg after landing a few blows on you.
• You return the egg to the group and they continue with their meal.

Three Insectoids will be brought to the Colosseum of Ashes from Kulbak Prison, and if you kept the egg one of them will be the Hatchling's mother;

The Insectoid hatchling you rescued from Kulbak Prison leaps from your satchel and races toward your opponents. You recognize one of the prisoners as the hatchling’s mother. Though she was feasting on her own eggs when you met her at Kulbak, she now extends her arms to embrace her hatchling. - Tome of Encounters (RPA-SQ1)

• You kill the Insectoids and free them from their imprisonment.
  • If you have the Hatchling it will abandon you in rage for slaying its kin.
  • You are beaten by the Insectoids and lose the Hatchling.
• You allow the Hatchling to be with its mother peacefully.

Members of the Mal'kanor are found to have been hired for labor by the Dwarven mining captain Borid.

A fight between a Hobgoblin and an Insectoid breaks out in the exercise yard of Kulbak Prison:

• Aid the Insectoid and its group the Blood Alchemists against their foe, and receive a gift.
• Aid the Hobgoblin and demolish the opposition.

Remaining motionless in a swarm of Insectoids will ensure safety, provided their mission is not to take you;

“If we stand perfectly still, we won’t be harmed.” - Gulpax, The Hive (GS-ADV3)

“The drones won’t attack unless they're provoked. Of course, they’ll be plenty agitated when you try to sneak into their hive.” - Gulpax, The Hive (GS-ADV3)