Help!

When I was still at home and Alex was still small; he went through a phase of 'awake-mares'. He saw bees... lots of bees in his room and it freaked him out. Of course there were no bees it was all made up in his head but it really got to him.
Claire is having similar experiences, only her nemesis isn't a bike or bees; it's snails. and hermit crabs. she is afraid that they are in her bed and on the floor around her bed. Her 'hallucinations' are not as vivid as AlMeads but all the same she wakes up screaming and crying and won't walk on the floor. Its scary for me as a mom since I can't do anything concrete. We have tried 'blowing them away' but that doesn't seem to work. With the ghosts a month back (thank you preschool television programing for introducing us to that lovely) we were able to simply clap three times and 'scare them away'. I am at a loss. It doesn't happen often but often enough to make my heart sad.
I know that during the day she oscillates between loving and hating to look into our large saltwater tank where the snails and hermit crabs live. Sometimes a snail or two will get out... we have an open top tank. They slime their way to the floor or onto the computer desk every once in a while. but we rarely see them moving, we usually find them just sitting on the floor, not moving and toss them back in.
I don't know what to do, so I'm asking for suggestions, even if you have no experience but have an idea, I am open. I just don't want her to be scared anymore.