Why do stars twinkle but planets do not?

Because planets are not too far away while stars are very far away

This is because stars produce their own light when gaseous changes takes place while planets receives reflective light from star like Sun.

Planets are celestial bodies on the sky which cannot produce light on their own so as they are called non-luminous objects but stars are not like that. Stars undergo atomic reactions inside them to produce light along with heat as they are called as luminous objects.

planets are non luminious bodies which do not produce light

BECAUSE THEY HAVE THEIR OWN ENERGY AND ARE TOO HOT

HI !!!
Stars twinkles but planets do not because stars have their own light and light is necessary for refraction but planets donot have their own light. we can see them due to reflection of light from the nearest star.
The second reason is that the stars have hydrogen or anything else which burns freely as it burns freely thus produces light.
Let take sun as example. Sun has hydrogen . Due to nuclear fission hydrogen is get converted into helium thus produces light and we all know that sun is a star.

THERE ARE TWO REASONS WHY STARS TWINKLE:
1. THEY ARE LUMINOUS BODIES WHICH MAKES THEM SHINE 
2. THE STARS TAKE TIME TO REACH OUR EYES.Y THE TIME IT REACHES US THE AIR MOVES THE LIGHT WAVES WHICH MAKE THEM TWINKLE. 

Planets are heavenly bodies which are non luminous.But stars have their own light and are far away so appear to twinkle

Light from other stars have to travel a long distance and have to pass through the earth's atmosphere to reach us. The layers of the atmosphere has air moving in different directions. When the light of the stars passes through the atmosphere, it is bent, which is why it seems to twinkle when we look at them.Stars do not twinkle when we look at them from space. The sun and the planets are close to the earth. The light coming from them is not bent due to the earth's atmosphere. Thus, they do not twinkle.