Danger

Dangers in Spore are things which are out to hinder your progress as an evolving creature or advancing race, and must be overcome or you risk anything from death to the collapse of your civilisation.

Tide pool phase
Enemies in the tide pool phase are generally micro-organisms (microbes) that are larger than the player's own microbe. From what has been seen of the tide pool phase, these seem to be, among other things, brown swarms that hurt the player's microbe when it gets too close. No hostile player-built microbes have been seen in the tide pool phase.

Creature phase
Other creatures in the creature phase may attack the player's creature either because the creature is a suitable food source, or because it is trespassing on their territory.