YT's are usually imported during our late summer to early winter months. Thats why they seem to show up all at once. For years I was buying, acclimating, keeping and breeding WC YT's. I had an 85-90% survival rate on imports and I was buying 15-20 snakes per year during my heyday.
Most took ft rodents and those that were finicky took chicks and chickrn parts.