The setup

  • Play as a single infant on a lot with no resident adults
  • Add an adult briefly to move in, then remove them with MC Command Center by aging them to child first and deleting
  • Goal is not money, but to unlock every infant milestone from Growing Together

The big loophole that makes it possible

  • Even without an adult, infants can travel using the map screen
  • Use travel to find a helpful adult in public venues, befriend them, then bring them home by scheduling a stayover
  • Disable daycare with a mod so the infant remains on the home lot while the guest sim acts as a caretaker

The caretaker plan

  • Befriend a sim at the gym or any public lot
  • Invite them for a multi night stayover so they autonomously meet needs
  • Build a tiny “caretaker suite” next to the infant’s space: bed, shower, toilet, sink, cheap kitchenette, changing table, high chair, infant playmat and tub

Milestones to target

Growing Together splits infant milestones into four groups:

  • Gross motor: lift head, roll over, sit up, creep, crawl, pull to stand, stand while holding, dance
  • Fine motor: reach, grab, put to mouth, pincer grasp
  • Firsts: first bath, bubble bath, try baby foods, finger foods, sleep through the night, trip to park, vacation, visit family home
  • Social: coo, laugh, babble, blow raspberry, blow kiss, peekaboo, wave, clap

Fast tracking gross motor

  • Equip infant with the wiggly trait for faster progression
  • Cancel non essential interactions so the caretaker prioritizes tummy time together
  • Remove distractions: delete stove, crib, trash can if they are pulling autonomy away from tummy time
  • Once the infant unlocks roll over to tummy, they can tummy time alone and snowball into sit up, creep, crawl
  • Place a low chair or coffee table to help trigger pull to stand and stand while holding

Fine motor and fun

  • Use the playmat toys to repeatedly trigger reach and grab
  • Try the bathtub early to unlock first bath and bubble bath, which also gives fun

Food firsts

  • After sitting, use the high chair to unlock try baby food and then finger foods
  • Good Appetite and Self Soother quirks help but are not required

Social chain

  • Keep the infant’s fun low then ask caretaker for help to spark playful interactions that lead to:
    • Coo, laugh, babble
    • Blow raspberry, blow kiss
    • Peekaboo (often triggered by caretaker autonomy)
    • Wave and clap are often easiest on the playmat

The tricky “dance” milestone

  • Infants cannot turn on stereos. Travel to a bar or lounge with a stereo and queue wiggle to music until dance unlocks

The travel based firsts

  • Trip to park: travel to any park lot and it should pop
  • First vacation: temporarily add caretaker to household, start a 1 day rental anywhere
  • Visit family member’s home: if the infant has no family, use adoption to link to a family, or quickly create a relative in CAS. Visiting should pop the milestone

Random chaos and gotchas

  • Celebrity sims can be unreliable caretakers. Stick to regular townies
  • Seasons thunderstorms can zap your guest. Keep them inside
  • Quirks are random. Self Soother and Loves Sounds are helpful
  • The milestone list can show impossible entries like “with Grim” due to internal tags. Ignore these

Minimal build checklist

  • Playmat
  • High chair
  • Changing table
  • Tub or shower with tub
  • Caretaker bed, toilet, sink, mini kitchen
  • Low surface for pulls to stand

What worked best

  • Wiggly trait for faster gross motor
  • Babysit autonomy by canceling non tummy time actions
  • Use the stayover system instead of nanny service
  • Travel to trigger dance and park firsts
  • Adopt or create a relative to finish the family visit

Result

With a single infant and zero resident adults, every non life milestone is achievable with patience and a cooperative houseguest. It is fiddly, but watching the infant go from flopping on the mat to crawling across the room and waving at townies makes the prequel to toddler rags to riches surprisingly wholesome and hilarious.

Source: https://www.youtube.com/watch?v=igJ2VFlHskU&ab_channel=onlyabidoang

Infant alone challenge FAQ

Can an infant live completely alone in The Sims 4?

Yes, but you need mods like MC Command Center to remove the last adult in the household.

How do infants get their needs met without adults?

By befriending a townie and inviting them for a stayover. That sim acts as a caretaker while the infant remains the only household member.

What milestones can an infant unlock this way?

All gross motor, fine motor, firsts, and social milestones except the impossible “live with Grim” one that shows due to a bug.

Why is the wiggly trait recommended?

It speeds up gross motor development like tummy time, crawling, and sitting up.

How do you unlock the dance milestone?

Travel to a bar, lounge, or any lot with a stereo, then use wiggle to music until dance unlocks.

How do you complete “visit family member’s home” without relatives?

Adopt the infant into a family or create a quick parent/relative in CAS, then visit their home to trigger the milestone.

What items are essential for the challenge?

A playmat, high chair, changing table, tub, and a small caretaker setup (bed, toilet, sink, mini kitchen).

Can milestones be bugged?

Yes, the milestone tracker sometimes shows impossible entries. Ignore those and focus on achievable ones like crawling, babbling, and waving.