Many evening it's just me at home with a 4 year old and a 21 month old. And these "girls nights" as we call them are some of the best times with my kids, but can of course also be some of the most challenging. The challenging nights are when the girls won't share, they scream at each other, and generally bother each other to tears (so many tears!). So I'm always looking for activities that we can do together that will keep everyone engaged and happy.
Enter modeling clay. We had some sequins, feathers, and googly eyes lying around in our craft drawer so I bought some modeling clay and we decided to make monsters. And the activity was entertaining ALL WEEK LONG! We made butterflies, unicorns, little alien men, snakes, and lots and lots of monsters. We even made a nest with eggs and a mama bird sitting on top. It takes about 24 hours for the clay to dry but now we have a display in our living room that the girls are so proud of (now to get fresh flowers for that vase!).
This activity really took hold with the girls when we realized we could stick the sequins in vertically and have them stick out straight. That effect didn't grow old!
So we recommend making creatures with your kids! They will love it.