When will my Survivors learn Abilities?

Every survivor has a special ability right from the start.

Abilities can be activated during a battle at night. Some abilities will cause area damage such as a Molotov and others may heal your Survivors. There are abilities that require you to select a target which you can do by tapping on the Zombie with the ability active. 

Some abilities scale with the level of your survivors. For example the critical damage ability.