Great quiz btw!
The large flying fox is described on its wiki page as feeding "exclusively on fruits, nectar, and flowers". There are similar articles for other large bats. Happy to adjust that if you have a better source that contradicts it.
Not sure where I got the crab thing from! Remember reading something but it was quite possibly a dubious source. Will have a look when I have a moment and if I can't find anything will change it :)