What are some things your pet does that show a surprising level of comprehension?

My back yard is like a tortoise festival. There is one spot they can get in under the fence which is visible from the back door. My dog has made friends with one of them. Now when she sees them crawl under the fence she begs to go out. If it is not her friend she flips them over. I told her not to do that any more as it hurts them and it was becoming a full time job for me to flip them right side. She stopped flipping them over. I'm still shocked she understood.