Ants, along with Bees, and most neuron-gel filled insects do not have endocannabinoid systems. As far as what is killing them, the resin is sticky and can greatly inhibit their mobility, terpenes are pretty interesting chemicals, most are a loose form aromatic hydrocarbon, however this isn't a blanket statement for that, but they could definitely cause insects troubles, terpenes are used to kill and repel insects frequently, the terpene Citronella for example.