Like when a dolphin or whale has deliberately approached people for help because they're tangled in nets & all- it's awesome. I can't speak for tarantulas because I don't have much experience with them, but I think the same is true of many snakes too, at least in my experience. Even some wild snakes you wouldn't expect to hold still for help without biting, but they do. It's as if they can sense you're not trying to harm them & they realize they need help. Nothing we can ever prove but something to keep in mind- I try never to underestimate an animal's intelligence- just because it's very different from ours, & even though they can't show expressions the way we do. I think that when you do good things for other creatures, it does good for you too- you feel it in your heart, don't you? And that makes your life better too, doesn't it? I think it does.