Cut the cardboard tubes as follows. You will end up with 5 baby bodies, 2 adult bodies and 14 ears.
Paper towel tube - Cut a 4.5" piece for dad, a 4" piece for mom and five 1/2" ears. (Toilet tube #1 - Cut two 1.5" bodies and two 1/2" ears, Toilet tube #2 - Cut two 1.5" bodies and two 1/2" ears, Toilet tube #3 - Cut one 1.5" body and five 1/2" ears.)
Paint each tube, inside and out, and a set of ears to go with each body.
Run a line of hot glue inside the ear and squeeze it closed to flatten it.
Use scissors to trim tops of ears to make them pointy.
Hot glue the ears to the top inside of the cardboard tube body.
Use pink paint to paint a line on each ear.
Glue on mini pom-pom noses and cut bows from felt and attach. For girls, attach bows up by the ears and for boys at the bottom front of the body.
Use Sharpie to add eyes and whiskers.
If you like, cut a simple apron from white felt for the mom. Cut out a small carrot from orange and green felt and glue to the apron. Glue apron in place. Glue 2 buttons to the front of the dad.