do they look like this?

If "yes":
The white projections are the larvae of the braconid wasp, Cotesia congregatus. Larvae that hatch from the wasps eggs, which are laid on the hornworm, feed on the inside of the hornworm until the wasp is ready to pupate. Such host hornworms should be left in the garden in order to conserve the beneficial parasites. The wasps will kill the hornworms when they emerge from their cocoons. They will also seek out other hornworms to feed upon and kill.
Want to attract this hornworm-destroying wasp to your garden? Then plant, and preferably near your tomatoes, such things as parsley, dill, yarrow, and mustard. Adult wasps feed on the nectar of these plants. Also, provide a source of water. A birdbath will suffice.
And finally, I hope you wont scream if you notice a host-hornworm on your tomato vines. For it means your garden is ecologically balanced, thanks to your non-use of pesticides.
http://www.agardenforthehouse.com/2011/08/when-not-to-kill-a-tomato-hornworm/
By all means move the leave-eating worms off your tomatoes but if they have the wasp larvae you may want to leave them alive somewhere else to foster more wasps as an easy control.