No chopping or mining

I watched the videos to make sure I wasn't doing something wrong, but the axe and pickaxe will not mine or cut down trees. I get near a tree and lick the left mouse button. The axe swings vertically and doesn't interact with the tree. I've backed up, tried to get closer, etc. Any ideas?

Thanks!

Just click once at a time. I'll try holding it down.
Thanks!