the string wont cause a block, it'll pass throughvery easily because they're able to break it down properly if they'reeating it. plus their diets should be very high in fiber. i noticedmine love chewing on string too. they used to love chewing on paper andphone books and then they started chewing on string and cardboard so ibring them string and cardboard.
most of the time, they aren't eating it.. they're just chewing