This is a Garden Orb Weaver spider if it is found on medium-sized shrubs, you don't need to worry because they are not poisonous, they just cause minor skin irritation. When web is touched at night, the spider will jump into the middle of the web.
It could either be wood-ticks, leaf-hoppers, grasshopper larvae, or Jiggers.
They can live without a head for two weeks because their natural organs harden over and heal for a period of two weeks before loss of blood and tissue damage kill it.
It may just be a mosquito bite, because after a while the hole where the skin was punctured scabs over and makes a black dot.
That was a very rude way to answer this person's question. They don't exactly have a mouth, they have a straw curled up under their head that extends to suck up whatever they wish to eat.
You are either thinking of an ichneumon wasp or a robber fly. Both are harmless to humans. Robber-flies are identifiable by the way they hover about when they fly. Ichneumon wasps are identifiable by what looks like an extremely long stinger on their back end, but it's actually a large radar in a way, because … Read more
I have seen bees get devoured by spiders, but if the bee is large enough, it will carry away the spider to shove into a honeycomb where a bee larva is curled up, so that when it awakens it eats the spider to help it grow.