I am trying to create a balanced ecosystem with three animals (sheephead fish, urchins, and kelp). Things go along great until (depending on the age of the urchins) all the urchins die simultaneously. Even though they are all being born at a different time and they are coded to age at the same rate, the urchins are all disappearing at the same time of old age. (I tested this by removing the code that has them die based on age. The simultaneous death stopped happening when this code was removed.) Can anyone help with my code?