Our young mealworm beetles will lay about 500 eggs each and live for up to six months. Keep them in wheat bran with potato fries for moisture. Change the wheat bran every 10 days and keep in a tray and over 70 degrees. It will take about 4 weeks before you can see the baby mealworms with your naked eyes. Put a potato fry in the tray each week for moisture but try not too much moisture or you will get mold in the wheat bran.