You must work on composition, all these are lacking. You seem to find comfort in center composition your images...get them off the center. Read up on the rule of thirds and how to center recompose when you shoot (middle focus point, half hold shutter, recompose)
1- not much interesting in the shot. Would of liked to see it closer up, although that is hard without a macro lens. Too much grass and other stuff, too straight looking down of an angle.
2- same as the slug, too centered and too much struff going on in the surrounding area to make the bee interesting. Bee also looks slightly out of focus
3- same as above 2
4- same as above 3
5- Cropping the image would help, as the above poster did.
Remember, keep what you find interesting in the frame, try and cut out the rest. Get rid of the clutter. Get the main subject off the middle of your frame (although that does work in some cases)