Western Tent Caterpillars are back in the Puget Sound. Tent Cats can do extensive damage to most deciduous trees when there numbers are up. Their favorite trees are alder, willow, cottonwood, and many other types of broad-leaved ornamental and orchard trees. These caterpillars increase in numbers every 7 – 10 years and they keep these numbers up for about 3 years. The Tent Caterpillars feed on these trees for about 4 – 6 weeks in the spring stating late April and lasting to the end of May first part of June. These critters can infest yards and do season long damage to your trees, and in some cases, shrubs. Contact Washington Tree & Lawn Care if you have any other questions.