If the object is a small foreground insect it will have thin dimensions. Flying in front of a bright background object like a cloud will give the illusion of the cloud showing through -- making the object seem to fly behind the cloud. However, it is just refraction of the light that occurs around all object edges. Because the width of the object is small compared to the amount of normal edge refraction, the bent background light tends to obscure the darker object.
Bright backgrounds can wipe out fine edge detail of foreground objects.