you can superglue them, yes. Get cyanoacrylic superglue GEL, make sure it's gel. I prefer the loctite brand from Home Depot, but as long as it's cyanoacrylic superglue gel it's fine to use. It's more difficult if they're not attached to some sort of snail shell or piece of rubble. In that case you can use a rubber band to affix them to a piece of liverock rubble, etc. They will eventually attach if you use the latter method.