When do you know moles are gone
haven't seen new mole mounds in a few days. When do you know their gone?
Clackamas County Oregon
Moles "swim" through the soil in pursuit of their invertebrate prey, so we only see their mounds when the prey (worms, grubs, other soil-dwelling insects) are near the surface. The moles likely are not "gone" from your yard. Instead, given the hot, dry conditions the past several weeks, their prey has most likely gone deeper into the soil where temperature and moisture levels are more favorable.
will they ever go away or will I need to hire an expert to remove them? I only see one mound every few days.
As long as food is in the soil, they may come to hunt those invertebrates. They won't "go away" because the area is habitat for them. Removing one or more animals will just open up territory for the next animal to come along, but it can be a temporary vacancy if the occasional mound is really an unacceptable situation.
what do I do? If they won't ever go away?
They are not going to ever go away completely. You can certainly work to exclude them from your area, but here are some FAQs you might find helpful. http://www.metromastergardeners.org/faq/index.php?action=artikel&cat=9&id=20&artlang=en