Do Fleas Die in Winter?
You may be expecting to see a DRAMATIC reduction in last summer’s flea population because of this year’s winter. But, alas, any fleas that were actively alive on your pets or in your house and most fleas which were in the cocoon or egg stage (and therefore protected from any freeze) are still alive and prospering, particularly in the mid and southern US. When the temperature reaches 70 degrees or higher and the humidity is high, fleas hatch, thrive and breed.