Add in that fish move sometimes fast. And lets not forget inconsiderate people who step between you and what your trying to take a photo of. My first visit of the year I spent the better part of the morning trying to escape a trio of selfish tourists who not only shoved between adults and the animals but little kids. They actually knocked one little one over and didnt even turn around to check on the kid.
Yeah, I've seen jerks like that many times. It's uncalled for. I always try to get my pictures, and let the kids see the animals. I can always wait for them to move on their own, so I can continue my picture taking.
Man Im glad I dont have kids of my own yet. I would blow my top if someone was that rude to my small child. I went this spring with 10-12 year olds who I explained proper behaviour to before we got in. I told them if I caught any of them stepping infront of anyone, especially smaller children, they would be standing back away from the barriers with me for the rest of the trip. I didnt have to worry though. They were particularily sweet to younger kids moving aside and encouraging them to step in front so they could get a better view. I rewarded their good behaviour with celebratory cool treats before we left for our what turned out to be 4 hour journey home with massive construction along most of the way.