How to Make Thumbnail of Post Stay Animated

When I upload my post with an animated .gif, the thumbnail generates into a new image and doesn’t stay animated. It will stay animated inside the post which is great. It seems to resize the .gif image and convert it into a static image because it generates an image with the sizing at the end of the original file. Is there a code to add or remove that prevents it from generating a new image for the thumbnail so it just resizes down as the gif?

Solutions Collecting From Web of "How to Make Thumbnail of Post Stay Animated"