Answer: Maybe. Isopods (pillbugs or sowbugs) tend to feed on decaying organic matter and can occasionally be found feeding around roots, particularly if the roots are unhealthy. Their role is part of nature's method of recycling and feeding the soil. If they are present in excessive numbers there may be cause for concern, however based on your description I am unable to determine if this is a problem situation or not. If you suspect they are excessive or if you suspect there is a below ground problem affecting your arborvitae, you might wish to consult with your local County Extension.
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