If they have never been fed worms by the breeder, it may just take a bit of time for them to get used to the idea of them being food items, keep on with it though as they are a great food, and definate favourite of all my salamanders. What kind of worms are you offering them? if its redworms bought from an angling shop or sold to use in a composter, they exude a foul tasting liquid which puts most[but not all] amphibians off eating them. small worms dug up in your garden will be the best bet
yes they are just garden worms- we've got a bin in the garden with eco-earth in and every so often we collect loads of worms from the garden and keep them in it. They get fed veg scraps and kept damp so they are good for the phibs. Will try again soon- but the sals had a nice big meal of woodlice yesterday so should be full from those