The Insecticons are insect-like Cybertronians that lived in the underground of Cybertron, near its core. They survived by the core's supply of Energon but they were forced to move to higher ground when it was infected with Dark Energon. Shockwave came into contact with them and manipulated them into joining the Decepticon ranks.
At some point, a large group of Insecticons made their way to Earth and sealed themselves inside stasis pods. Those Insecticons now serve Megatron in their fight against Team Prime. But after some time, Airachnid returns and tries to take over the ship but failed as Soundwave bridged them on Cybertrons' moon. Airachnid, now a zombie, sucks the energon out of her minions.
The Insecticons were native to Cybertron, when the Great War began they were seen as tiny specimens as Shockwave, the Decepticon's scientist began experimenting on them and made newer, larger breeds of Insecticons. While searching for the Dark Spark alongside Starscream, Soundwave, Laserbeak, and Rumble, Shockwave came across three sentient Insecticons named Kickback, Sharpshot, and Hardshell.
After the War
When Arcee and Jack traveled to Kaon, there was an Insecticon guarding the Decepticon Capital. Arcee tried to distract it while Jack carried on with the mission. The Insecticon subdued Arcee and attacked Jack as he was fighting a swarm of Scraplets. Jack managed to direct the Scraplets' attention to the Insection, and the Scraplets quickly killed the Insecticon.
Starscream then found Airachnid with an Insecticon. Airachnid ingored the Starscream's question concernign the Insecticon's origins and ordered it to attack him, with Starscream barely escaping.
She then challenged Megatron to fight the Insecticon. After a battle, Megatron triumphed and killed the Insecticon. Airachnid found that defeat unimportant, as she had found an entire hive of Insecticons underground that she could control.
Against The Nemesis
Airachnid planned to have the ultimate revenge against the Decepticons, so she ordered the entire Insecticon army to attack their command ship, the Nemesis.
While the Vehicons and Megatron battled the Insecticons, the Autobots arrived. The back fleet of the Insecticons attacked the Autobots, except for Arcee, who went after Airachnid. After a battle underground, Arcee trapped Airachnid inside a stasis pod, preventing her from controlling her army.
Returning To The Decepticons
With Airachnid no longer controlling the Insecticons, they returned to their natural instinct of serving Megatron, and joined the Deception army. Though tensions grew even greater when they began to insult the soldiers. Megatron sent Hardshell to retrieve Tox-en.
Hardshell failed but returns to claim to Megatron that he had snuffed an autobot during battle. Megatron was pleased and ensured that Hardshell had his kill. Though Hardshell fought a couple of Vehicons and was caught by Knock out. Hardshell met his end when he faced against Wheeljack. He was able to take down Wheeljack, but was killed by a human in Wheeljack's ship. The insections returned to tell Megatron of Hardshell's demise.
Return Of The Queen
Airachnid would later be freed by the Terrocon C.Y.L.A.S. and regained control of the Insecticons. However, they were all transported to a desolate planet by Soundwave. At present, they serve as food for their now Energon-hungry queen.
Another Insecticon by the name Razorhorn worked as a bounty hunter alongside the Decepticon Shadelock and the renegade Autobot Roughedge. They were employed by Starscream to track down the Weaponizer Mini-Cons. However, they eventually ran afoul of the Bee Team and was shipped back to Cybertron on Prime Force One as prisoners.
- Sharpshot (killed by Grimlock in Fall of Cybertron)
- Kickback (killed by Sludge in the Beast Hunters comics)
- Hardshell (killed by Miko in "Hurt")
- Bombshock (killed by Airachnid when she became a Terrorcon vampire in "Thirst")
- Razorhorn (incarcerated on Cybertron as of "Worthy")
- Decepticon Island Insecticon (incarcerated on Cybertron as of "Decepticon Island, Part 2")
The physical appearance of Insecticons differs in each appearance. In Fall of Cybertron, they are mostly land-based Insecticons with large jaws and six legs called Swamers with a purple and green color scheme. However, some of the Insecticons are smaller, flying bugs that spit acid at their targets. Finally, a new breed created by Shockwave called Bruisers are very large, as large as Grimlock and have a mostly purple color based paint job.
However in Transformers: Prime and Robots in Disguise, the Insecticons are very different. They are all taller than most transformers, even than Optimus Prime and Megatron. They usually have a green color job with a single optic streeched across their face (like Cyclops from X-Men), though Hardshell and Razorhorn both have variations to their coloration that help them stand out of the crowd. They transform into Hercules Beetle-type insects which make loud fly sounding noises.
- There seems to be discrimination between the Vehicons and Insecticons. They both constantly insult each other and believe the other to be inferior.
- Insecticons seem to be another form of "vermin" on Cybertron than others.
- Insecticons often snarl and growl than speak. When they do speak, it's either because they're giving orders or talking to their fellow beings.