i run away every day and return every night, i am disliked by flowers and a thiefs delight

Darkness?

The answer to the riddle you presented is "shadow".

Explanation:
A shadow is formed when an object blocks the path of light, causing a dark shape to appear on the surface behind it. Here's how the different clues in the riddle relate to the answer:

1. "I run away every day": Shadows are formed during daylight when an object obstructs the path of sunlight. As the sun moves across the sky, the shadow created by an object also moves.

2. "And return every night": Shadows disappear at night when there is no direct source of light. However, once daylight returns, objects cast shadows again.

3. "I am disliked by flowers": This emphasizes the absence of sunlight caused by the shadow. Flowers need sunlight for photosynthesis, which is crucial for their growth and survival.

4. "A thief's delight": Shadows can be advantageous for thieves trying to remain unseen or hide their actions. They offer a form of concealment or camouflage.

So, the answer is "shadow", which aligns with the clues provided in the riddle.