Peter didn't notice at first. Onboar the Milano was hot, sticky, and cramped, like any other M-class spaceship, so, once all of the team had settled into the fact that they were essentially sharing a houseboat in space, they adopted the spacer standard of 'steamer gear'- the bare minimum needed to cover oneself. Gamora settled on a sports bra and exercise shorts most of the time, scars ah her ribs be damned. Peter typically just wore shorts, and Drax his pants. Groot wore just as much clothing as he did landside- that is to say, none at all.
Rocket was the last to finally strip to shorts himself, staying in a flight suit for a full two weeks after Peter and Gamora stopped caring, before switching to a thin tank top and shorts. He still had reservations about baring his back, even with his fur starting to re grow from a much-improved diet.
Since those that wore clothing only wore full gear in the presence of a holocall or being docked, when Peter went to grab a shirt one morning three months into their collective living arrangement and found none in his drawer, he wasn't concerned. He figured they were all in the wash, which they didn't do often because the water filtration was crap and Rocket needed parts they couldn't get near the Londa Quadrant.
He got three shirts back after he ran a cycle. Eh, whatever. The machine was fickle, they probably got shot through the pneumatics to someone else's' room. He had all of his underwear at least. He didn't want to send Gamora an undue present.
Drax or Rocket would probably just laugh it off and make cracks about the size of his package.
It was when he couldn't find his jacket the following day on a supply run that he new it wasn't the laundry- that always went to a specialty cleaner's along with the rest of his prozoi leather garments. They'd bleed under normal washing.
He tried Gamora first. Maybe she took it to a cleaners? She'd piled up quite a bit of clothing for the nearby laundromat that morning.
"I have not touched any of your garments, save the pair of pants that had been bloodstained. And you gave those to me for cleaning."
Strike one.
Drax, maybe?
"Which one of your red leather jackets, Quill? All of your jackets are both red and leather."
"The one with the red lining, goes to my hips?"
"The only one I have seen is the long one, which I remember borrowing a week ago when Gamora needed to go on a stealth mission. We used it to cover much of her noticeable skin color."
"I've gotten that back already, thanks."
Strike two.
Groot didn't wear clothing, but, well, seeing as Drax and shirts were never on speaking terms and yet had been in possession of one of his jackets, it was possible Groot had borrowed it for another reason.
Peter rapped quietly on the bulkhead of Groot and Rocket's room, mostly because Rocket hadn't left their shared space in three days, other than to use the facilities. When confronted, Peter, Gamora, or Drax got a "go away, yes, I'm fine, ya think Groot would be so calm otherwise? Just leave 'im my food," followed by an irritated whine of a growl. Groot was the only one allowed in and out, and was spending most of his time locked up in the room with Rocket, exiting occasionally to get food or more blankets. Not a single spare pillow or afghan was left in the common areas by this point, and oddly enough, Groot was also constantly running the kettle to fill water bladders of boiling liquid.
Was Groot collecting clothing, too?
"Groot, buddy."
"I am Groot," Groot replied quietly from the other side of the bulkhead.
"Did you take my jacket? Kinda chilly on Suma, and I have some client meetings later. I'd like it back if you have it."
"I am…"
"Jus' hold on," gruffed Rocket uneasily. "Groot'll slide it out the bulkhead for ya."
"What's your problem, anyway?" Peter asked, waiting for Groot to unlock the bulkhead for him.
"In a rut," Rocket replied, hoarsely.
"Dude, if you need help, just ask us. Is it about that gun design Nova wanted? You need some inspiration?"
"Not that kind a' rut, Star Dork. The ah, well, y'know how occasionally Gams gets super testy and starts getting weird cravings for pickles?"
"Wait, you don't have a period, do you?" Peter asked incredulously. "Do you… need tampons or-"
"NO, you d'aast idjit. A rut is the male version of that. Did nobody teach you biology?"
"Oh. OH. I'll uh.. leave you to your… wait, are you… with my…" Peter was blushing furiously, remembering his research on procyonidae.
"NOT LIKE THAT YA IDJIT. Fine. Come in."
The door clicked, unlocking, and Peter slid it open. The strong scent of musk filled the tiny space, and Rocket was curled up in a massive blanket fort; only his nose peeked out of the pile of pillows, blankets, and about ten of Peter's t-shirts, as well as two of Gamora's jackets and the deep-space quilt from Drax's bed. Rocket hesitantly pushed himself out, in steamer gear, but carrying a hot water bottle wrapped in another of Peter's shirts.
"I just… feel like I need to be with something warm. It's like I feel I'm supposed to be sleepin' with someone else- ah, not like that, just, y'know. Curled up with someone," he said, holding the Peter-facsimile tightly in his forepaws. "It's stupid, and I'm sorry. I shouda asked first. Or let you all know. It happens like twice a year. Better than bleedin' once every six weeks like Gams."
"Look, I know you don't like the R-word but Gamora and I did some research in case we ever needed to get you medical care," Peter said, noting the bristling of fur at the word 'medical'. "Adult male raccoons sleep alone, unless it's, ahem… season. It's the only time they share dens. I'm guessing Groot being a tree isn't helping any. You want to curl with one of us fleshbodies, right?"
Rocket looked down. "Don't bother you? I feel kinda… feral… when I rut. It's taking all of my energy right now just to think and talk. I kinda just wanna eat and curl up somewhere. S' only lasts a week, maybe two, but yeah…"
"I can't speak for Gamora or Drax, but I don't mind. I was always pissed at Yondu for stealing my Care Bear as a kid."
Rocket squeaked once, jumping up in Peter's arms and curling around his neck, purring.
"Night…" Rocket mumbled gruffly before promptly falling back asleep. Peter uncoiled Rocket from his neck and carried Rocket back to his own bunk in his arms.
Yawned.
Looked like Peter could use a nap, too.
For the one of you that cares (I wanted to be a zoologist when I grew up so cut me some slack here):
Raccoons typically rut in the late fall or early winter, although raccoons in warmer climates like Florida can rut up to three times a year. Rutting behavior includes marking territory, cuddling with females, and being allowed to sleep in a female raccoon's den (the only time males are allowed to do this outside of their first year with their mother). Once the rutting period is complete, the males go back to their own den. They do not raise kits with females. Females will keep their kits with them for a full year, even though raccoons are fully mature after 6-8 months. Female raccoons with kits are given highest priority in raccoon society, and coons without kits will often give mother raccoons food.
If you find a den of kits without a mom, don't move them. Since moms raise kids alone, she's probably out getting food. If the kits look like they are freezing, or several days have passed, then rehab them.
Raccoon PSA over.