It could have been a raccoon or a skunk. When you used DE, did you just sprinkle it around? A light application just doesn't do it. Get a large bag and spread it over the area about half an inch thick. Make sure you have at least a 6" perimeter past the farthest entrances. Force the ants to WADE or BURROW through the stuff. Apply it as close to dark as you can (and still see to work), after the ants have 'gone to bed'. When they go out in the morning to forage, they will have to go through the DE. I have dealt with thatch ants, and tried all the methods I could find: boiling water, vinegar, cold hose water, poisoned bait, and more. The thick layer of DE is the only thing that worked. By the way, if you have yellowjackets in underground nests, and a few helpful skunks, get the cheapest bottle of syrup you can find, and pour it on the nest at dusk. You will probably find another hole as soon as the skunks discover the treat. They love sweet stuff and yellowjackets. Sue Sue

Good suggestion. It's a great barrier, but doesn't kill many before they catch on. Think of it as a water-less moat. I have been using food grade diatomaceous earth (also called fossil shell flour) for years with great success. But be careful - IT IS HARMFUL IF BREATHED. =================================================================== From Occupational Safety and Health Administration - Material Safety Data Sheet http://www.domyownpestcontrol.com/msds/Insect_Dust_msds.pdf : Health Hazards: Signs and Symptoms of Exposure: Exposure may result in coughing, wheezing, shortness of breath, tightness of chest, irritation of the upper respiratory tract and damage to lung tissue. Medical Condition Generally Aggravated by Exposure: Pre-exiting asthma, bronchitis, emphysema and other lung and respiratory ailments may be aggravated by exposure to dust. Possible effects of single exposure: Acute exposure may cause upper respiratory irritation. Inhalation: Irritations of the upper respiratory tract and lungs may result from accidental or chronic occupational exposure to the dust of this product. Dust may also cause lung damage when inhaled. =================================================================== I use this product in limited situations and not applied to large areas where it will blow around. You have to be careful applying it because it's a very fine powder that blows easily. I don't pour it, I carefully use a spoon on a day with no wind, and wear a good N95 particulate respirator (dust mask) with an exhalation valve. I also use it very sparingly in the back of pantry shelves instead of insecticide. Lasts for years. Outside, I use it in rainproof containers blocking the ant path by suspending the item with chains. Using two long stainless steel eye bolts connected together with a 1" tall nut (they're called rod coupling nuts) through the container sealed with silicone. I use washers and a regular nut against the coupling nut to secure the bottom of the container to the eye bolts. To protect the DE from the rain (it only works when dry) I attach the cover (even a heavy non rusting pie plate will do) to the threaded eye bolt with nuts and washers making sure there is a gap above the container. If the cover touches the container, they will bypass the DE. Then, I connect the chains together so they have no way down the chain without walking through the DE. For the container, don't use plastic that breaks down in the sun, gets brittle and cracks. Use a stainless steel cup, doesn't have to be deep, 2" is fine. Similar in size to a 8 oz cream cheese container. Here in So Cal we have Argentine Ants. Very pesky critters that cooperate with other ants to become the earth's dominant ant. My local colony stretches 600 miles from San Diego to San Francisco. Multiple queens, insecticide just stimulates more nests. (https://en.wikipedia.org/wiki/Argentine_ant). Since they recognize poison bait after a while, you don't eliminate them. You steer them with DE. They did manage to cross a small 2 inch diameter container (1 inch path) of DE by forming a chain of their bodies to get to a hummingbird feeder. Might have been a fluke though, since the path was shortened a bit by a dead beetle carcass. Anyway, to be sure, I suggest at least a 4 inch diameter container forming a 2 inch barrier around the chain. Don't forget, one leaf touching ANYTHING gives them an alternative path. This includes the chain above the DE, so mount the DE container high above the plants. Also run drippers high above the plants, or submerge drip tubing through the DE in the container running from the chain to the edge. Use bailing wire to secure the drip line so it never moves above the DE. Better yet, run the tubing in parallel with the eye bolts through holes in the container sealed with silicone. As for the subject at hand, I haven't bothered to suspend my strawberry containers yet. They're sitting on the ground. Usually the ants are happy with 10-20% so I just grow more plants. Win win. So far the truce has held, but if they get greedy, I'll up my game. (pun intended)

irpingold: Use a product called Terro, specifically intended for sweet-eating ants. Place drops of it on cardboard around your patch. The active ingredient in Terro is boric acid, which is non-toxic to humans. No need to spray anything. Terro is carried back to the nest and wipes out the entire colony. It is widely available at Wal-Mart and many other marts. Don Yellman, Great Falls, VA

Carpenter ants need all their cohorts to survive. And that includes the egg-laying queen. It's a very unlikely occurrence to receive the entire "family" in mulch.