38. Question: What will happen to the insecticides and herbivores that we put in our lawns. Well I believe your question is about what will happen to the herbivores if we put insecticide to our lawn. Well they will be poisoned or worst die. Insecticides are usually made to get rid of the insects and pests that eats our flowers, vegetables and other plants in our lawn. Now, if an insect was able to get a plant with insecticides, it will be poisoned then sooner or later die.