Hiking with your kids is an great way to get them out of the house and into nature.
Here are our top choices of "nature" hikes around Sacramento (excluding more urban walks), in no specific order. The focus was on some shorter, and easier ones that would be best for families with younger children:
Quite a long picturesque trail along the American River with several entry points, so you can do a distance that best suits your family, and choose between paved or unpaved routes. A good choice with fun places to stop.
Take a walk through the trails and enjoy the wildlife. There are a couple shorter loop trails to choose from--the Cosumnes River walk, and the Wetlands Walk, both of which begin a the visitor center.
The Blue Heron Trail loops will take you around the lakes an marshes to see the local birds. It's short and well paved, so it's ideal if you need to push a stroller.
After learning about the area at the nature center, hike through the loop trail, and see the plants and wildlife residents in action. Guided tours are available.
The Seasonal Wetland Loop is a good flat trail that isn't too long (about 3 miles). Bring binoculars to witness one of the best bird watching sites in the area.
A bit of a drive, but well worth it. There are many trails for hikers of all levels, as well as other outdoor activities, like mountain biking, horseback riding, and rafting, and fishing, if you want to change things up.