I live in a 1925 brick, craftsman bungalow in Memphis, TN. This brick/mortar problem has puzzled some old-timer masons and the state agricultural extension service.The roof of the porch extends over the driveway to form a portico, supported by two square brick columns. Every year with the start of warm weather, some sort of beasties/insects have been gradually "eating" into the mortar. They are not visible but they have already eaten the mortar about an inch into the columns, leaving a fine dust between the bricks. (see pics) I have tried insecticides and bleach to now avail. (see pic). Do you know of a remedy for Mortar-Eating-Beasties, or can you refer me to another source, Please? I assure you this is NOT a case of the mortar just being old. There is no evidence of this anywhere else on the house. Sorry, wasn't able to upload pics. Thanks for your help!