Good to know. Yep, I have placed them outside (my Cymbidium and Oncidium) because I read they need more sunlight than Dendrobiums. And I did notice ants around the roots of the Cym. Hopefully those have been removed with me washing the roots and removing all the medium around before repotting.
Do Cymbidiums and Oncidiums need more sunlight? (and can it be direct light?)