Inspired by the real life Cat House on the Kings, whose website can be visited here. They adopt out their cats and are always accepting help in form of donations and volunteers!
Note: This challenge can be adapted for other pets, too!
Also, this is my first time posting+writing a challenge, I hope you enjoy!

Intro)
You’ve always been a bit cat crazy, but after coming into ownership of four kitties of your own, it’s gotten more… intense. You’ve become inspired to build your own shelter just for cats! Everyone says that you’re in over your head, but as long as you have some help you should be fine, right?

Requirements)
The Pets Expansion
Nraas Master Controller and Nraas Mover (Or any other mod that allows for overstuffing)

Part 1: CAS
Creating Your Founder)
There are only two restrictions on the founder’s creation (Although cat-related apparel and the Cat Herder LTW are encouraged):

• They must be either a Young Adult or Adult
• They must have the “Cat Person” trait.

Creating Your First Cats)
You can make up to four cats in CAP to start out with, no more than that. These cats can look however you want them to, there are no set restrictions.

Part 2: The Shelter
The shelter should be built on a large lot; 64x64 is optimal. There should be plenty of space for all of the facilities that the kitties (And whoever lives on your lot!) need. Money cheats ARE allowed during initial construction, so that all required facilities can be built. When starting out, you may only build the required facilities using money cheats; all extra buildings have to be built with leftover money or during the course of play. The grounds should be completely fenced in to prevent any residents from leaving. There are several buildings that are required for the shelter:
The Founder’s Home)
The founder (And any Sims that you have work for you) will live in this house. It should be small and unobtrusive, preferably in a corner of the lot, to save space for all the cats. There should be all basic amenities, as well as any extra knickknacks that your Sims might want.
The Quarantine Room)
Cats who have fleas should be immediately placed here to receive a flea bath. The facility should first be equipped with 4 bathtubs. The facility should also have some cat play items and pet houses in case the patients can’t get immediate treatment.
The House)
This is one of the main shelter areas of the facility. It should be equipped with 1 large kitchen for making food, and, when first constructed: 5 litterboxes distributed around the building, play equipment, and 5 places to sleep. Daily meals should begin distribution and/or preparation here.
The Transition Shed)
Cats who are new arrivals should be kept here for a week before being allowed to roam the main grounds. Starting out, this shed should include 2 cat play structures, 1 scratching post, 2 feed and water bowls, and 6 beds. There should be 2 litterboxes, as well.
Feeding and Cooling Stations)
These should be distributed around the property. Each should include 1 pet house, 2 food and water bowls, and 1 litterbox
The Kitten House)
Any kittens you take in or are born on the lot will live here until adulthood. At the start, this building should include 3 beds, 2 feed and water bowls, 1 cat tree, 2 litterboxes, and 1 scratching post.
Kennels)
Start out with one kennel complex for the first colony. Resident cats that don’t live in the house will probably hang out here. The first kennel complex should be fenced in and include 5 beds, 3 feed and water bowls, and 2 litterboxes.
As time goes on, you can upgrade these buildings with more supplies. These should hold you over for a while, though, while you take in more cats. If you want to have extra facilities, here are some suggestions:
A senior cat area
A parking lot for visitors
Public restrooms for visitors
A garden with a pond for fishing

Part 3: The Rules

• After initial construction, no money or mood cheats are allowed unless told otherwise. Construction cheats are allowed at any time if you have the funds. Other cheats are allowed if the situation requires them.
• Only build onto your facility if you have the funds.
• Freewill MUST be on high for both Sims and Pets.
• If you have Woohooer, enable autonomous Woohoo for cats, for some added challenge.
• None of your furry little residents can leave the lot without a staff companion or having been adopted by a family.
• The founder and all staff members CANNOT have a job outside of the shelter. How else will the cats get what they need? They can, however, make extra money off of hobbies, such as painting or gardening.
• Your founder is allowed to marry/have kids. If you want to do some kind of legacy challenge alongside this, go ahead!

Part 4: Everyday Operation
Visitors)
Your shelter should be open for visitors for a set period of time every day. This is so that people can come and interact with the cats and so you can look at potential new staff members. I recommend using this to summon visitors to your lot. Set the visiting price at something reasonable, and maybe include a place to eat or buy supplies on-site once you get the funds. Try to keep track of your cats’ relationships with visitors to see if there are any potential adoptions or staff members. Don’t forget to talk to your visitors, too!
Staff)
If you become good friends with another Sim and they get along with your cats, you can add them to your household as a staff member! Make sure that you have space in your human home beforehand, and make sure to check their traits. If they have over 3 undesirable traits, it’s time to look for a different Sim.
Good:

• Cat Person or Animal Lover
• Charismatic
• Friendly
• Good
• Handy
• Loves the Outdoors
• Either Loves the Cold or Loves the Heat
• Natural Cook
• Neat
• Night Owl
• Nurturing

Bad:

• Absent-minded
• Childish
• Clumsy
• Couch Potato
• Evil
• Grumpy
• Hates the Outdoors
• Hot-headed
• Insane
• Mean-spirited
• Neurotic
• Slob
• Unlucky
• Unstable

Taking in Residents)
Outside of random events, you will need to pick up residents for your shelter. After the morning feeding and cleanup is done, you’re free to go out on the town until evening. Look for stray cats and interact with them briefly before adding them to your household.
Once a week, you can also adopt a cat through the phone. Try to keep some age variety!
Whenever you take in a resident, you can add $500 to your funds to help support the new cat.
Adopting out Residents)
If you see that one of your cats has a particularly good relationship with a visitor, invite that person over to see if they’d be a good owner. If they pass your test, move the cat into their household (Make sure that they have what they need to care for a cat!) and add one of the following amounts to your funds:
$1250 for a kitten
$1000 for an adult
$750 for an elder
Random Events)
If your game is lacking variety, you can roll for a random number up to 10 and have one of these events occur!
1: 5 kittens are given to your shelter! Adopt 5 kittens from the phone and roll again for how much money you receive:
1: You receive no money for your troubles. Oh well.
2-3: You receive $500.
4-5: You receive $1000.
6-7: You receive $1500.
8-9: You receive $2500.
10: You receive $3000!
2: An anonymous donor has donated a generous amount of money to your shelter! Roll again to see how much you receive:
1-2: You receive $10000!
3-4: You receive $15000!
5-6: You receive $20000!
7-8: You receive $25000!
9-10: You receive $30000!
3: Uh-oh, looks like one of your newest residents is pregnant. Choose a female cat that you’ve recently taken in and use Nraas Master Controller to impregnate her. Make sure she’s comfortable to term, and don’t forget to name the kittens!
4: Looks like there’s a case of the kitty cold going around. Isolate a quarter of your residents from the rest of the population in a fenced-in enclosure for at least 2 weeks. Only staff should be allowed in, to feed and check up on the sick cats.
5: A pretty bad storm just hit the facility, and now you have to pay for repairs. Take $2500 out of your funds.
6: You’ve taken in a stray mom and her two kids. They all have fleas, but other than that, they’re relatively healthy. Give yourself the standard funds for each cat, but immediately place the family in quarantine.
7: Yikes, one of your new arrivals has a bit of a bad temper. You might need to keep a close eye on them. Add a new cat to your shelter, but give them the Aggressive, Destructive, and Noisy traits. You can create them in CAP if you wish.
8: A major news source just did a story on your shelter, and donations are pouring in! Every day for the next week, add $1000 to your funds.
9: A famous blogger just published a smear article on your shelter. Looks like nobody wants to visit for a while. Close your shelter to visitors for a week.
10: An old cat sanctuary in the area is closing in a few days, and wants you to take in some of their residents! They’ll be paying a larger fee of $750 for each cat due to the short notice. Roll again to see how many elders you should add to your shelter.
1-2: Add 3 elders.
3-4: Add 4 elders.
5-6: Add 5 elders.
7-8: Add 6 elders.
9-10: Add 7 elders.

Part 5: Goals, Lose Conditions, and Scoring
There is no specific win point for this challenge, just try to run your shelter while adopting out cats and keeping everyone healthy and happy! There are, however, ways to lose the challenge.
You lose if:
Over half of your cats are taken away
Your founder dies with no staff members
I know that a lot of people like scoring themselves, so here’s a points system:
+50 for every cat taken in
+200 for every cat adopted out
+100 for every staff member added
+10 for every cat that masters Hunting
+10 for every skill your founder or staff members master
-50 for every cat that dies
-100 for every time cats are taken away
-10 for every litter of kittens conceived by accident
-100 for every time you reach $0
-150 for every time the repoman visits

Feel free to share what happens in your own games below, I'd love to hear about them!