Scientists have discovered fossilized dinosaur eggs. Just like us, dinosaur babies started out walking on all fours until they began to get their balance. Because of their large heads (which make it difficult to move fast), it is also believed the parents would have cared for the babies for some time.
I have a little house in which I live all alone. My house has no doors or windows, and if I want to go out I must break through the wall. What am I?