Teach your children to respect animals and the world around them. Teach them that nature isn't their toy and that their actions have consequences. Teach them compassion for other beings and creatures.
A lot of people on this post are focusing on pets, which is fair but not what I intended. Any decent pet owner would teach their children how to respect their pets, their dogs and cats and the like, but pretty much everyone neglects lessons about other animals and nature in general.
Teach your kids that:
nests are important and that they need to be left untouched and undisturbed
they should NEVER take an animal that they find outside and that if they find an injured animal, they should give it space and find an adult to help
wild animals in general need a wide berth and that ANY animal can be dangerous if it feels threatened
wild animals are not pets under any circumstances
it's kinder and very easy to catch and release bugs outside instead of killing them
all bugs are important, even spiders and wasps and other scary ones
everything in nature has a job in general, and everything has a role to fill
something being scary or creepy does not mean it deserves to die
Let other living beings have autonomy. They're living their own lives, doing their own thing. There's no reason to disrupt them. If your paths cross, let them be. If you have to have to interact, then any interact should happen with the least amount of harm possible (which also includes stress).
Also that an animal becoming too used to people can be deadly. Just because you aren't going to hurt it doesn't mean that other people won't and if the animal thinks humans are safe, it might not run away when it needs to to save its life
