For this you have to use javascript. Easiest would be some kind of implementation with jQuery/javascript implementation.
You could also find this easily on the internet, this took me 3 seconds just by typing the "video on hover" in google: https://codepen.io/gil--/pen/bNxZWg
Html: 
<div id="videosList">           
<div class="video">
    <video class="thevideo" loop preload="none">
      <source src="https://giant.gfycat.com/VerifiableTerrificHind.mp4" type="video/mp4">
    </video>
  </div>
</div>
You need to watch for hover event on video tag.
var figure = $(".video").hover( hoverVideo, hideVideo );
Now you add a function that plays video on hover: 
function hoverVideo(e) {  
  $('video', this).get(0).play(); 
}
And when user leaves the video you add another function: 
function hideVideo(e) {
  $('video', this).get(0).pause(); 
}