Fleas are a nuisance, but they do more than itch. They can cause all types of issues beyond discomfort and can quickly invade and infest a home or even a commercial facility.   In this episode sponsored by ARCSI, a division of ISSA, urban and medical entomologist Jennifer Gordon shares her thoughts on what the cleaning industry and others need to know about the flea, what it eats, how it infests structures, what it means for public health, and what can be done to eradicate a flea infestation.