According to Dr. Kim Williams-Guillén, who invented the fake eggs, making the eggs look like sea turtle eggs was easy. First, they made them into the right size. Sea turtle eggs are as big as table tennis or golf balls. Dr. Williams-Guillén also put dimples on them to make the fake eggs look like real turtle eggs.
The challenge, however, was to make them feel real. Real sea turtle eggs are leathery, soft, and squishy. Thankfully, once the fake eggs were put into the nests, they got covered with mucus and sand. It then became hard to tell the difference between the fake eggs and the real ones.