no i have never had a problem. but i have heard they are killers...???? guess i'm just lucky? this is in my small reef tank. as such it gets alot of brine shrimp. because this tank also has my seahorses,2 male and three female. other tank mates are three green chormia's a sailfin tang,maroon gold stripe clown,and a piscico trigger. at least twice a week i feed it 2 or three large krill. and i'm sure it can sting but i have never been stung by it???