Red Shouldered Bug

Despite the fact that the soapberry bugs belong to the family of insects referred to as the scentless plant bugs, they are actually quite redolent. When disturbed, soapberry bugs release a pungent, odorous substance that discourages predation and renders them unpalatable (possibly even poisonous). It is thought that their bright coloration and strong odor serve to advertise their unpalatability to potential predators; this phenomenon, a common type of antipredator adaptation, is known as aposematism. Their aposematism is effective and permits them to fearlessly aggregate on trees, rocks, and man-made structures to sun themselves. These aggregations often consist of hundreds and sometimes even millions of soapberry bugs.

they were feeding off a seed pod,which does seem to be a common behavior with these insects. Feeding in groups must be for ensuring safety/