Juveniles may feed every 14 days, but be sure to monitor defecation, with 3 feedings for every defecation as a minimum. One of the tricks used to elicit a feeding response in a tempramental Tropidolaemus wagleri is to irritate, or anger, the snake by using long tweezers or forceps and tapping the snake on the tail with a mouse, and then the snout if needed. Manipulation of the snake can also anger it enough to strike. If a strike occurs with a fickle feeder, stay still, or exit the animals field of vision. Once the animal has grabbed the prey item they will typically swallow it, but movement may startle the animal and cause it to lose interest.
Evenings are the best times to try to feed.
I have soaked my animals for up to 3 days. Roosting is a sign of good health in adult Wagler's Vipers. Give the animals a number of branches of varying width. Thinner branches seem to be preferred. If a snake stops roosting it is generally a sign of a problem.