Most of the information I gathered on Irken biology I got from here: (well, add michelle8936 and . deviantart and a . com with no spaces to this and should get it) #/d4wz67m Now, credits to the people he also got some of his info on are in his own comments. :D Sorry to leave it like this, but I'm writing the next one now, and it was already over 2,000 words xD ENJOY! (sorry for uploading it FOUR times, kept finding mistakes, GUH)

Dib had kept his promise, regrettably, and knocked on Zim's door the next day. He had been sitting comfortably on the couch, the relaxed feeling from the night before spoiled slightly by Dib's "interrogation" session. Zim was kicking his feet when the knock came. The computer's voice droned over the room. "It's Dib.."

"Dib-stink?" Zim had asked, and jumped off the couch.

Dib was swaying, bored, on his feet as he waited for Zim to open the door. When he did Zim was hiding behind the wood, his disguise already taken off for the day. Dib walked in and turned to see Zim close the door behind him.

"What do you want, Dib-stink?" Zim asked. Ignoring the insults yet again Dib sat on the couch, seeing Gir sitting in the kitchen looking at the wall on the table.

"What's wrong with Gir?" he asked.

"He's turned off. Usually I talk with him for a while, but his screaming was too annoying the other day; and I have yet to turn him back on again," Zim said, hoping to answer any other Gir related questions that had formed before they could be ask. He had been expecting Dib at some point, but immediate questioning after just the night before was a bit much and he didn't know if Dib's new interrogation would lessen his impatience, or heighten it.

"Oh. Understandable, I guess. So, I just had more questions, and-"

"It's obvious you have more questions; you haven't given up in asking them for QUITE a while," Zim stressed. He shot Dib a look that said he should cut to the chase and avoid any unneeded questions. "What do you want to know now?"

"Well... biological things," Dib said. "For instan-"

"What do you mean exactly by... biological," Zim asked. He stressed the final word; his posture clearly showing he wasn't pleased by the term. His antennae fell flat against the top of his skull and his eyes narrowed dangerously. Dib stopped himself from gulping and held eye contact, refusing to back down.

"Just tell me if I'm getting too... personal. I don't know anything about Irken biology. You can even ask me questions if you want!" Dib hastily added; trying to avoid another death glare. If looks had ever killed Zim's glares would've committed multiple murders by now.

"...Fine," Zim spat. He sat down on the couch reluctantly. They each sat on opposite sides of the sofa. Dib squirmed uncomfortably in the silence. Not even the television was turned on. A bird chirped and Dib turned to Zim.

"So! Um... I dunno... I guess my first question would be... since I haven't seen under your uniform in any way..." Zim gave him a look and Dib looked in front of him hurriedly. "Uh! M-my question was... do you have any.. I dunno, any kind of natural armor?"

"... You have very odd questions, Dib-stink," Zim commented. As Dib turned to give a retort, Zim continued. "No, we Irkens don't have any natural armor. I assume your reference would be an... arm.. arma..."

"Armadillo."

"Yes, armadillo. The armored ball that is an animal. Irkens have no need for any sort of armor. Our paks and weaponry are all we need."

"So you're just skin? Like a human?"

"I am not human," Zim stated.

"I know. But, you're all skin like one."

"..Yes, I am."

"What are your antennae for?" Dib asked. He reached over to touch one, and Zim hissed, smacking his hand away.

"NEVER touch them," he ordered. Dib quickly sat back, his hands under his legs.

"Sorry! Sorry! But, what are they for?" he asked again.

"Hearing, expression… I told you all this already!" Zim shouted. "Don't ask a question I have already answered!"

"Then what do they feel like?" Dib asked. He considered reaching for them again, but stopped suddenly when he saw Zim's antennae flatten against his skull. "What's that mean?"

"It means I'm close to mutilating you," Zim answered. Dib pursed his lips. "..Anger. Irritation. Annoyance. Any negative feelings are expressed when they are flattened. This includes sadness."

Dib nodded, knowing Zim had only gone into a further explanation to keep him from asking more questions than necessary. He waited as Zim continued.

"When they're perked up," he said, giving the motion. "… it means that I'm happy. Or that I'm listening to something, or searching for a sound."

"When they twitch? I've seen them twitch before. Sometimes a little, and sometimes a lot, but I've always wondered wh-"

"Curiosity!" Zim shouted, purposefully cutting Dib off from his rambling. Dib heard a small growl from Zim and his antennae flatten again. "They also do that when I'm relaxed and they pick up sounds. Irkens have superior hearing compared to a hyuumans, and therefore they twitch a lot due to the constant noises on this dirt ball."

"Anything else?"

"Why don't I just give you all the information I know so you'll stop asking?" Zim asked. Before Dib could answer with an obvious yes, Zim continued. "Antennae are very good indicators of any Irken's present mood. When at almost forty-five degrees in an angle, it means that an Irken is calm and relaxed; this is usually the default position you see them in. If they're raised higher, the Irken is alert. And if they are lower, it means an Irken is wary about something. There are actually three different positions for anger – the lowered, the flattened and the forward. The lowered position shows only slight annoyance, while the antennae being flattened against my skull indicates I am angered, particularly if they are twitching. The vital difference between this position and that of the antennae facing completely forward, is that during the latter the Irken is very angry, and will likely kill whatever is angering them. They also give off pheromones, but humans cannot smell them, of course."

"Why can't I touch them?"

"Irkens are not allowed to touch each other's antennae, so what makes you, Dib-stink think that Zim would let you?"

"It's not like they'd hurt for me touch, would they?"

"…They… they are very sensitive. So yes, it would hurt very much if you pulled one. Some enemies of the Irken Empire have discovered this, and used it as a torturing method before. But we also use them for balance. And In case you are wondering, while a males are pointed or kinked at the end, like mine; a females are most often curled," Zim said. He stood up and walked to the kitchen. Dib followed, sitting at the table. "I left to get away from you."

"So, are there any other sensitive regions? I mean, with humans our stomachs are pretty... sensitive to pain and feeling."

"According to your biology textbooks they are also the housing of most of your organs."

"Right. How many organs do Irkens have? And you didn't answer my last question."

"I am aware," Zim said irritatedly. He shifted his weight. "I am not answering the first quest-"

"You have to!"

"No I do not! Your constant questioning annoys me anyway!"

"Fine! Then just answer the second."

"We have three main organs that are organic. The PAK is considered an inorganic fourth organ. It was organic at one point, I believe," Zim said.

"Really?" Dib shouted. Zim gave him a glare and he shut his mouth.

"YES. Anyway, the three organic organs are our heart, brain, and squeedilyspooch. The PAK is sort of a second brain that helps operate the body, therefore also being our life support. The PAK will grow with the Irken as they get taller. But since height is a form of status in Irken life, most of us are soldiers or have a more civilian status. It's rare that we grow as tall as our Leaders; hence their name the Tallest."

"Cool," Zim heard Dib mumble from behind. He ignored it with nothing more than a smirk and continued.

"Because Irk is all metal, buildings, training centers, and snack bars we have a thick ozone layer that eventually made our skin pale. I'm not sure if the layer is natural or not anymore. The skin of Irkens is green mostly because of the high… what's the human term.. copper content, I believe it is, in our blood. The oxygen we breath makes it so our skin appears green since the veins are close to the surface. Our blood also contains a natural anti-freezing chemical that allows us to live on our planet, which is very cold. Again, thanks to the ozone layer blocking out the Sun most of the time, I imagine."

"You know, you resemble lizards, but you don't feel like one. You feel more like leather."

"..And?"

"Uh… I don't know. Um.. so did Irkens always have PAKs?"

"I believe so. It used to be organic, and even had the legs as well. But we Irkens changed it into a metal machine over time because it was harder to damage that way; and eventually became more efficient that way. But we have yet to discover a way to keep from dying when it is removed. I am not going into detail about THAT," Zim said when he saw Dib's mouth open in question. "There is more on the PAK. It is only compatible with Irken biology. If attached to another creature, it will destroy them in just as long as it takes for the Irken to die. So stealing one is highly idiotic. They also record our status in the Irken society. Or can be upgraded to place an Irken in a different ranking or position. The PAK also houses four mechanical spider-like limbs that can be used as laser cutters and shield generators, an audio and video communicator, an ID and monetary transfer plug, an anti-gravity device, a jetpack, an atmospheric processor, personality, charging cell and an auto-reset. They're very useful. Although, before modern PAK technology an Irken would only live about 150 Earth years, or about 15 years on Irk. With the new PAK, we live much, much longer. Irkens can live for several millennia now. And they give no need for food. But on the occasion that an Irken does decided to ingest something, no waste is created because the PAK uses every food molecule to power itself."

"Why haven't we come up with something like this?" Dib blurted out. "Man, we're dumb!"

Zim smirked again as Dib banged his head on the table. "Earth-pigs are far younger than the Irken race."

"That's hardly an excuse," Dib mumbled.

"Zim is surprised you are not writing this down," Zim said. Dib sat up again.

"Don't need to. I'm recording it," he said, holding up the device. Zim eyed it warily. He felt no immediate danger, as no one believed Dib to begin with, so audio recording could easily be put off as faked.

"..Whatever," he said. Dib raised an eyebrow at the proper use of the slang term.

"What about the other organic organs?" Dib asked, setting the recorder on the table. Zim sat across from him, feeling as if he was being interviewed now instead of just being asked questions by Dib.

".."

"Your eyes? How do they work?" Dib asked.

"First, they come in many other colors than the red and purples you've seen from me, Tak, and the Tallest. They are much more superior to a human, in the way that they allow me to see in the night almost as if it was daylight. And our form of sight and the spectrum in which we see is also superior. The natural Irken eye can see light within the electromagnetic spectrum as well as your own field of sight, which I also learned from your biology textbooks, therefore giving everything we look at a light colored sheen. However, Irkens are unable to focus on one object because we lack what you call pupils, but have a great panoramic view; the relative size of our eyes only increase the field of sight to a total of 180 degrees on the horizontal plane. This allows us to not only have a much greater field of view in battle, but also allows us to see the heat signatures given off by the enemy because of genetic enhancements over time," Zim stated. "We can also use them to breathe, using tissue similar to a human lung. But, as I experienced once while I was here because of the Planet Jackers, I learned they can also pop out if hit hard enough. Luckily there was no permanent damage."

"How come you're so much faster and more flexible than a human? Do your claws and foot talons help with that at all?"

"Our claws and talons do help with speed and climbing. We are agile even on rough surfaces thanks to the talons acting as spikes when we run bare-foot. The claws and talons can move independently, and our claws can secret a deadly toxin that can even erode thin metals," Zim said. He enjoyed the face Dib made and added to the information. "Irkens are immune to the toxin of another Irkens claws, of course."

"WOW! This is amazing!" Dib exclaimed. "Okay, tell me about your real brain! The organic one!"

"Later. Zim must go down to his lab," Zim said. Dib was about to object when Zim turned back to him. "Join me if you really intend to ask me more. But no questions on the way down, I wish my vocal chords to rest."