Each animator group includes a default range selector. You can replace the default selector, add additional selectors to an animator group, and remove selectors from a group.
Selectors are a lot like masks: You use selectors to specify which part of a range of text you want to affect, and by how much. You can use multiple selectors and specify a Mode setting for each one to determine how it interacts with the text and with other selectors in the same animator group. If you have only one selector, Mode specifies the interaction between the selector and the text—Add is the default behavior; and Subtract inverts the influence of the selector.
If
you delete all selectors from an animator group, the values of the
animator properties apply to all characters in the layer. This is
useful because properties of the text specified by the Character
panel cannot otherwise be animated (except by using Hold keyframes
on the Source Text property itself).Use a Wiggly selector to vary a selection within a specified amount over time. Use expression selectors to use expressions to dynamically specify how much you want characters to be affected by an animator property.
Common selector properties
Range selector propertiesRange selectors include the following properties, in addition to properties common with other selectors:

Using different Shape options, you can significantly change the appearance of an animation.

Wiggly selector propertiesThe Wiggly selector includes the following properties, in addition to properties common with other selectors:
Expression selector propertiesExpand the Expression Selector property group and the Amount property group to reveal the expression field in the Timeline panel. By default, the Amount property begins with the expression selectorValue * textIndex/textTotal.
Expression selectors allow you to express the selector values for each character. The expression is evaluated once per character. Each time it is evaluated, the input parameter textIndex is updated to match the index of the character.
Apply the Text
Bounce or Inch Worm animation preset to a text layer to see how expression
selectors can be used. To see all expressions on a layer, select
the layer and press EE.In addition to the expression elements you use elsewhere, you can use the following attributes to animate selections in any number of interesting ways:
