Constant supervision and reminders are necessary. To a toddler, exploring his world is a stronger need than following his parents' directions. Toddlers are often seen as challenging their parents' authority when they disobey their parent's rules. Toddlers cannot be expected to control their own actions. When they see something they want to look at or touch, they will go for it .
Some toddlers explore with their mouths.
At this age most rules need to be limited to those that deal with safety. Childproof your entire house. Do not rely on your toddler to keep himself out of danger. Place your valuable or breakable items out of reach. There is no benefit to having temptations so close to your very curious toddler.