Skitters are a species of apparently intelligent insect/humanoid creatures enslaved by the Espheni and serve as the ground troops and lower-level commanders of their operations. Early on, they were widely thought to be responsible for the Invasion of Earth. They move quickly on six legs, attack with formidable claws, and possess a tough exoskeleton. Skitters are functionally nocturnal (Grace) and communicate using radio waves. They are able to use harnessed children to communicate with humans. They are also referred to as "Cooties" by Pope's Gang. The harnessed children refer to them as "guardians" (Death March).
According to Rick Thompson, Skitters are morally repulsed by the concept of harming one's own species, a trait they seem to have been implanted with by the Espheni.
While performing a dissection, Anne and Lourdes find a harness beneath a Skitter’s exoskeleton, revealing skitters are the enslaved subjects of the Espheni. Skitters may have once been a different type of life form, as the harness seems to genetically modify the host.
It is revealed in the episode "Mutiny" that the harnesses will gradually transform the harnessed kids, a process that can continue even if the harnesses are removed. Examples of this can be seen by Rick's ability to stick to walls in addition to his enhanced strength, speed, and agility. In addition to this Megan was shown to have scales on the sides of her head, and possibly even more parts of her.
In "Hatchlings", it is revealed that the Skitters are the mutated forms of a race called the Dornia, who were believed to have been completely wiped out by the Espheni. However, at least one appeared to have survived, and is communicating with Tom.
The Skitters were once known as the Dornia, they lived in peace on their home planet, numbering in the billions. They were known to have a similar appearance to what they look like now, but without the exoskeleton.
Over 1000 years ago the Espheni came into conflict with the species known as the Dornia. The Espheni then proceeded to invade the Dornia home planet, harnessing most of their race, and transforming them into slaves. The planet was then supposedly irradiated by the Espheni Motherships, but a portion of their race survived and engaged the Espheni in an intergalactic war, pushing them further and further away from their own home planet. The enslaved Dornia, now referred to as Skitters, served as foot soldiers in the service of the Espheni all the way up to the invasion of earth. However, not all of them are mindless slaves, as there are Skitters that have been able to break free of Espheni control over the years and created a resistance against them that has existed for over a century.
For 6 months it was believed that they were the aliens responsible for the invasion of Earth. This was until a scouting party in Boston, MA witnessed the Espheni commanding them.
They "harness" children using a parasite to control the children's minds so they can communicate. They appear to have armor that covers their body except for their head and legs. It is revealed in the episode "What Hides Beneath" that the Skitters are in fact harnessed themselves by a very tall humanoid race of aliens, known as Espheni, revealing the Skitters are not the true invaders, but are instead unwilling slaves to the Espheni.
The fact that humanity was able to create an organized resistance so quickly, and witnessing first hand how courageously humanity fought back against their oppressors made it clear to the Skitter rebellion that, with humanity's help, they just might have a chance.
In Season 5, due to the vast majority of their skitters running wild as a result of the Espheni power core's destruction, the Espheni begin genetically engineering a new breed of mindless skitters and Black Hornets from scratch in a hatchery located near Chinatown with the goal of destroying the 2nd Mass. The hatchery's destruction and the death of the Espheni overseer in charge of it caused the hundreds of engineered skitters, hornets, and waspers to run wild as well.
They are able to command bipedal Mechs as well as airships all though these war machines lack any sort of pilot. They also can command small groups of harnessed children. A skitter can not fight with a gun or knife. But can wound a human with a blow from one of its legs. However in Worlds Apart an unidentified Skitter weapon, similar to a cattle prod was seen in use.
The cattle-prod like weapon aesthetically resembles something produced by the skitters, and lights up in the same way that a harness does when activated by them. It seems to produce an electrical shock current that is extremely strong and is used as a torture method by the skitter's when working with the Espheni. So far this is the only weapon that is explicitly seen or mentioned to be used by the skitters.
The Skitters were the first species to give a brief description of what their planet of origin is/was like. While the planet is still unnamed, Red Eye claims that their home world was much like Earth in regards to its atmosphere, diversity of life and amount of water cover.
Its current status following the Espheni invasion is unknown but it can be assumed that their home world is much different now than it was prior to the Espheni's invasion. This is supported by Red Eye who stated that it was much like Earth. This was later indirectly explained by Cochise in The Pickett Line when he explained how the Espheni's defense network will irradiate all organic life on Earth.
The Skitters original species and home world have now been revealed by Cochise. The Skitters were a product of an enslavement of the Dornia. However not all Skitters are proven to be Dornia, as the Espheni have conquered many other planets.
Skitters have vaguely reptile-like but also several insect-like features. Skitters walk on six legs, but have a roughly humanoid torso with two clawed arms (for a total of eight limbs). Instead of having composite or compound eyes like many insects, Skitters have lizard-like eyes with slit pupils. They can breathe Earth's oxygen atmosphere without external aid. Earth's temperature is also compatible with them, though they are said to have slightly higher tolerances to both heat and cold.They may not have a true exoskeleton - their armor may just be an organic type of bulletproof vest. Skitters possess an internal bone endoskeleton, muscles, and circulatory system much like Earth vertebrates. Skitters have red blood, suggesting their blood contains iron-based hemoglobin, just like human blood. They do need to sleep, and often prefer to do so by hanging upside-down from the ceiling like bats, clustered together if there is more than one. It is not clear if they are nocturnal, because they have been seen either sleeping or active at different times of the day. Skitters who are in control of a group of harnessed children tend to sleep with them. Tom Mason points out that this is similar to human soldiers in combat zones, who try to grab quick naps whenever they can at any time of day.
Skitter mouth parts are fairly different from most earthly vertebrates, and it is physically impossible for them to make the sounds of human languages. They communicate with each other using radio frequencies which are inaudible to humans, but can be picked up by radios in the form of interference. It is unclear exactly what range this radio communication has, but it is known the range is not infinite - Skitters must be within a certain distance of Mechs, harnessed children, or other Skitters to communicate with them in this manner. Skitters can communicate through harnessed children, but it is not clear if they can understand human language on their own. Skitters can thus direct groups of harnessed children in combat, though if they are only being controlled by one Skitter, they can only focus on one objective at a time.
In Silent Kill, it was discovered by Anne that unlike humans, Skitters have no bone separating the soft palate of the roof of the mouth from their brain. Because there is nothing but soft tissue in between, forcefully driving an object into the back of a Skitter's mouth will easily kill it. Of course, one would have to get dangerously close to a Skitter in order to do this.
A little over two years after the invasion it was revealed the Skitters have a more evolved form, known as the Black Hornet. Unlike Skitters, the Black Hornet has four wings, making it capable of flight. It also has blue eyes and an elongated tail.
In Hunger Pains, it is shown that ingesting Skitter flesh is poisonous to humans, and rapidly causes internal bleeding, and for the body seemingly decompose from the inside out.
In Non-Essential Personnel, it is shown that the Skitter's six legs are able to help the Skitters jump large distances.
Little is known about Skitter society and beliefs. Currently their civilization is almost totally subsumed by the Espheni and whatever it may have once been prior to the alien invasion and enslavement is unknown.
According to Rick Thompson, Skitters are morally repulsed by the concept of harming one's own species, a belief similar to that of the Espheni and may have come from them originally. The Skitter Rebellion, however, has shown no hesitation when it comes to killing enemy Skitters.(On Thin Ice)
Skitters tend to stay clustered together if in groups.
Currently there appears to be a deep split within Skitter society between the enslaved Skitters and the rebel Skitters that was able to break free of the Espheni control and will stop at nothing to bring their enslavers down.
Now as of the Espheni Power Station being destroyed, many of the Espheni Overlords fled, leaving the skitters with no leaders. Most of the skitters are being killed easy, and the rest acting like wild animals, fighting over food and killing each other in the process.
This skitter attacked Tom Mason in a food warehouse. It and a Mech were waiting, patiently, for a chance to attack someone, and the 2nd Massachusetts Militia Regiment soldiers happened to be by. When Tom Mason's team were in the building, the skitter surprised and attacked Hal, who was saved by his father. In the meantime, a Mech was attracted by the shooting and started to chase Tom. Since Hal had distracted it, Tom managed to destroy it by rigging a cart with C4 and rolling it in the Mech’s direction. Later, the skitter reappeared and tried to kill Tom, but failed. Dai, in turn, killed it with a blow in the head. It mumbled something in a strange alien language before dying. It is unknown what it said as no one could translate.
Tom Mason captured this skitter, returning to the 2nd Mass as both a prisoner of war and the subject for study. When it woke-up, it attempted to communicate by having Rick, a previously captured teen who'd had his harness removed as part of an experimental operation, to put his harness back on and serve as a translator. The effort failed, as Mike removed the harness again, angering the alien and, perhaps, endangering Rick's life. This skitter remains a prisoner, though it has started to form an attachment to Tom and Anne, but remains scared and angered by Harris and Mike, most likely due to their previous actions toward it. It killed Harris in self-defense when he attempted to inject it with a lethal serum. Anne Glass finally killed it by stabbing a surgical scalpel into its soft plate.
A Skitter that was killed by Pope's Gang. The 2nd Mass dissects it and uses it to learn more about the insides of Skitters. Its corpse helped the 2nd mass discover about communication through radio signals. Later Anne and Lourdes dissect it and discover it and the skitters are harnessed.
Skitter that led a group of harnessed children, one being Ben Mason. It ordered the children to lay down in a circle and fall asleep before using its leg's to cover them with its body. As they fell asleep, the skitter lovingly pets their heads. Hal, pretending to be a harnessed kid, stabs it in the head but was not successful in initially killing it. During the ensuing melee, Tom Mason shoots it with an arrow allowing Hal to complete his work with the knife.
Skitter that attacked Jimmy Boland and almost succeed in taking him or killing him, however it was killed by Weaver in the 2nd mass base before it could capture or kill Jimmy.
This skitter was on the Espheni commander's ship while Tom Mason was captured. It escorted Tom along with Karen Nadler to the Espheni to discuss humanity's surrender. Eventually, Tom manages to take its weapon and shock the commander, the Skitter then knocked Tom out. After Tom and the others were released the Skitter ordered the Mech it was with to kill all the people except Tom. Later in Shall We Gather at the River it was seen, slightly injured from the explosion on the bridge, near the 2nd Mass, the bug that was taken out of Tom crawls into its left eye. Ben and Jimmy, while patroling in the same area where it was located, came into contact with it. This skitter defends itself by attacking them resulting in Jimmy's death. It then pays Ben a visit, while Ben is out alone in the woods, and Ben's harness remains begin to glow for reasons unknown. In the episode Love and Other Acts of Courage Red Eye sends Rick back to the Second Mass and asks to be taken back to base. While there Red Eye tells Tom Mason through Rick that the Espheni did the same thing to the Skitter's home planet that they are doing now, and that he is the leader of a group Skitters resisting the Espheni and offers Tom Mason the chance to form an alliance between the Second Mass and the Skitter Rebellion. Red Eye later escapes the base after Captain Weaver tried to have him killed because of Rick's intervention.
This skitter was present at the factory, where several kids where being harnessed. It appeared to be in charge of this factory and was eventually killed when the 2nd Mass gained access to the harnessing room, where the kids were being harnessed.
This skitter took over command of the Skitter Rebellion after "Red Eye" was killed shortly before the 2nd Mass destroyed the Unidentified Overlord Cannon. He informed Tom and Col. Weaver that Karen Nadler had taken over for the Espheni commander Tom killed several months earlier. During the 4 months that the 2nd Mass was separated, the Espheni captured the remaining Rebel Skitters (including Paint Face) and genetically engineered them into mindless drones, as Black Hornets.
This Skitter was questioned by Anne, and told her about a hybrid and the New Order before being stabbed.