After the chicks are 3 weeks old, if it’s warm outside (65-70 degrees at least) and sunny, feel free to let them have a little “outdoor time”! Put them in a wire cage or erect some other temporary housing and place it in the sun, making sure they have access to water and shade if they need it. They’ll absolutely love digging around in the grass. But don’t leave them unattended! At this age they’re very good flyers and susceptible to predators.
By 6 weeks of age your chickens are ready to move outside. Trust me, you’ll be thrilled to get them out of your house.