You can glue them but it is very difficult due to their slime. I have had the best luck putting some crushed coral or crushed live rock in a small container such as a tupperware. Then take a piece of bridal veil material (available at Joanns fabrics) stretch it over the top of the container and put a rubberband around it. Let the container sit in your tank for about or at least 1 week. Try not to mess with them for at least that long. After they have attached to a piece of rubble you can then glue the rubble to whatever rock that you want to attach them to. Make sure you use superglue GEL or some kind of coral glue.