Probably not a question you get often in Vermont! At my home in Addison County I have a small patch of Eastern Prickly Pear cactus (opuntia humifusa) in a well-prepared and drained bed measuring about 2' x 3' on the south side of my garden shed. The bed contains a mixture of sand, succulent potting mix, and small stones. The cacti have thrived outdoors year-round for about 10 years, and they blossom beautifully in spring. The past two years ants have invaded the patch and carried sand up from below to the point where some cacti are becoming almost fully buried (see photos, before and after ants). I understand that ants and cacti often go together and may even be symbiotic, but in this case there seems to be potential for serious damage to the plants. Any suggestions? I've thought of vacuuming the sand with a shop vac to clear the buried cacti.