Window Load as Animation Trigger
<Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="" Height="300" Width="300"> <Window.Triggers> <EventTrigger RoutedEvent="Window.Loaded"> <BeginStoryboard> <Storyboard> <DoubleAnimation AutoReverse="True" RepeatBehavior="Forever" Storyboard.TargetName="tt1" Storyboard.TargetProperty="Y" Duration="0:0:1" To="-90" /> </Storyboard> </BeginStoryboard> <BeginStoryboard> <Storyboard Timeline.DesiredFrameRate="60"> <DoubleAnimation AutoReverse="True" RepeatBehavior="Forever" Storyboard.TargetName="tt2" Storyboard.TargetProperty="Y" To="-90" Duration="0:0:1" /> </Storyboard> </BeginStoryboard> </EventTrigger> </Window.Triggers> <Grid> <Ellipse Width="75" Height="75" Fill="Firebrick" Stroke="Black" StrokeThickness="1"> <Ellipse.RenderTransform> <TranslateTransform x:Name="tt1" X="-75" Y="90" /> </Ellipse.RenderTransform> </Ellipse> <Ellipse Width="75" Height="75" Fill="Plum" Stroke="Black" StrokeThickness="1"> <Ellipse.RenderTransform> <TranslateTransform x:Name="tt2" X="75" Y="90" /> </Ellipse.RenderTransform> </Ellipse> </Grid> </Window>