In most flowers, pollen is a kind of fine dust. If an insect comes along it will be powdered by it, and thus it can carry it to another flower to pollinize it.
In orchids you can find in every flower two polliniums shaped like little clubs. On one side of each pollinium there is pollen, on the other side a kind of glue. When an insect visits the flower, the pollinium detaches itself from the flower and sticks to the insect's head. Right on spot. The insects continues with one or two protrusions on its head. When it forages on another flower, the end of the club with pollen touches its stigma and it will be pollinized. If everything goes well.
See here a small butterfly, a Meadow Fritillary (Mellicta parthenoides) on a Pyramidal orchid (Orchis pyramidalis) in soft evening light. Yes, it is beautiful!
But it does not move at all! Is it asleep? No, it is exhausted, maybe starving amidst flowers full of nectar.
Orchid polliniums are sticking on the proboscis and make it impossible to put it into the spur and get to the nectar. In the pictures they are visible like small yellow and violet objects.
The butterfly tries to get rid of the polliniums, it rubs one of its legs against them. In vain, the glue is too strong.
Another try. No, it does not work.
It has no more energy to go on. It can't even fold its proboscis in the right way. Is it going to survive? No, if the glue does not unstick, this butterfly will die from hunger, thirst and exhaustion.
You can not help it with tweezers, it is too delicate. And you can't take wild butterflies to the vet. No, impossible.