Eggs that have gone way past their expiration date in the fridge can be composted. But if you’re going to toss whole eggs into the compost bin, make sure to crack them open and stir them around with other organic matter. When whole eggs are put into the compost, the natural heat can “cook” the eggs and create gas inside. Eventually, the buildup becomes too much, and they can explode. It’s not dangerous, it’s just very smelly. And don’t give your pets old eggs to eat; if it’s unsafe for you, it’s unsafe for them.