Active Ingredient

• The active ingredient in Bayer lawn insect killer is imidacloprid, a synthetic compound that mimics nicotine. Imidacloprid kills ants, fleas, grubs, ticks, chinch bugs, crickets and other sucking and chewing insects by disrupting the nervous system, which causes death. Imidacloprid binds to the nerve cells of insects more than to the nerve cells of vertebrate animals, according to the National Pesticide Information Center.
  
  

Potential Hazard to Lizards

• Bayer lawn insect killer's product safety warnings advise that children and pets be kept away from the treated area until it has been watered and allowed to dry. Lizards on or near the lawn area may be exposed to the insecticide.
  
  Lizards are vertebrate animals like dogs, cats, squirrels and other wildlife. Pesticides that are harmful to pets are also harmful to smaller vertebrate animals such as lizards, according to wildlife specialist Terry Wessmer of North Dakota State University.
  
  

Benefits of Lizards in the Garden

• Lizards feed on beetles, ants, wasps, grasshoppers and spiders. Some species feed on snails. Lizards, hover flies, parasitic wasps, ladybugs, green lacewings, stink bugs and assassin bugs are insects and wildlife that help maintain ecological balance in the garden by ingesting potentially harmful insects.
  
  Lizards are beneficial wildlife that feed on the same insects that Bayer insecticide kills. Loss of food source may result in lizard migration to neighboring gardens that are pesticide-free.
  
  

Precautions

• The product label warns avoiding contact with skin and eyes and breathing its dust or spray. Farmworkers have reported dizziness, breathlessness, headache, confusion and vomiting after exposure to insecticidal products containing imidacloprid.
  
  Insecticides with imidacloprid such as Bayer lawn insect killer have not been identified as carcinogenic by the Environmental Protection Agency.