A player may attempt to breed one baby animal per habitat at a time. Attempting to breed a baby animal costs a set amount of pet pennies specific to the species involved. Also, a set breeding period must elapse before the results are determined. During the waiting period, animals in the habitat cannot be moved to the Zoo Depot unless the player chooses to cancel the breeding attempt.
A habitat can accommodate one baby animal per male / female pair present. A breeding icon will appear on the habitat and in the habitat's menu when breeding is possible. If a habitat does not have any eligible male / female pairs, or if it already includes a baby animal for every adult pair present, the breeding option will disappear.
If the attempt fails, another attempt can be made, requiring the player to pay the breeding fee again and wait for the breeding period to elapse again. If the attempt succeeds, the player is awarded experience (the amount depends on the species) and the baby appears in the habitat. The baby may be sold for PP, but the amount is lower than the breeding cost. It is not possible to earn a profit from breeding animals.
While breeding can be attempted with any species for pet pennies, babies may be bred with a 100% success rate and with no waiting time for zoo dollars.