In March, they would look for earthworms or their castings on the ground near their tunnels, and this was a sign of spring because it showed the earth had thawed and that it would not freeze again. With your soil thermometer, record the temperature of the soil each day. Look for robins pulling worms from the ground, worms in rain puddles on the pavement and for worm castings near the openings of their burrows in the soil. Castings are small mounds of digested food left at night by worms on the soil which look like tiny mud-covered raspberries. On the left-hand side of this page you'll see a blue owl button.
Females follow a week or two later.
Finally the first young of the year hatch. Depending where you live, robin families in your region are at a particular point in this annual cycle. The timing of these activities varies with latitude. In fact, as a rule of thumb, it's estimated the timing varies by 10-15 days for every 5 degrees north in latitude. Please include the name of your school and your location so we can credit you properly for your answers.