Frustrated

We bought some of those « mole deterrent » sonic thingys a few weeks ago. Almost overnight the mole hills vanished. They have been very successful - until the past couple of days. One hill appeared, but we thought it had been put off by the beep and buzz made by the thingy. Then, today, a deaf, insensitive mole moved in. This pic does not cover the 11 hills that appeared overnight. More drastic measures needed. 
Anyone know where Bill Murray got his dynamite from in the film Caddyshack?