bxslider-control-hover.css

/**
 * Controls hover fade effect!
 *
 * Change class name -> slider_class_name
 */

.bx-controls-direction {
	opacity: 0;
	transition: opacity .25s ease-in-out;
	-moz-transition: opacity .25s ease-in-out;
	-webkit-transition: opacity .25s ease-in-out;
	}
.slider_class_name:hover .bx-controls-direction{
	opacity: 1;
	}