Image descriptions – appear only when Image is hovered over or clicked on?

I’m trying to display an image gallery which contains pictures of my company’s leadership. When each image is clicked it should display their bios under the thumbnail gallery (which is about 5-columns wide and 3 rows high).

Based on the Codex page over here, I have managed to get the thumbnails to display. However the Image Description is only appearing for the last image that is arrayed under my $args.

How do I get the image description to appear only when the mouse hovers over the image, or when it clicks the thumbnail?

Any help would be greatly appreciated!

Here is what I have been trying to do:

<?php $query2 = new WP_Query( 'post_type=page&page_id=40' );?>

<?php if ($query2->have_posts()) : while($query2->have_posts()) : $query2->the_post();
  $args = array(
   'post_type' => 'attachment',
   'numberposts' => -1,
   'post_status' => null,
   'post_parent' => $post->ID
  );

  $attachments = get_posts( $args );
     if ( $attachments ) {
        foreach ( $attachments as $attachment ) {
           echo '<ul><li>';
           echo wp_get_attachment_image( $attachment->ID, 'full' );
		   echo '</li><li>';
           echo apply_filters( 'the_description', $attachment->post_content);
           echo '</li></ul>';
          }
     }

 endwhile; endif; ?>