True. However, I'd argue that in order for the symbol picked to remind individuals of danger and not, say, a decoration, it needs to not only be recognisable at a glance, but fundamentally it needs to make sense for the message trying to be conveyed. For example, if red is chosen to be the universal colour for danger, not all cultures present will see it that way - either the project will need to put out a colour guide, or that document with everyone's theories being circulated around should not only have colour definitions, but also have each heading done in red so that it reinforces the danger.

[ a beat. and then, clear rue coming through in the tone of voice: ] Sorry. I might be overthinking things. Here's maybe something more practical and on topic: if the choice of animals is birds, then I'd suggest for the wings to be spread and outside of the body. A symbol of a fish has its fin tucked along the body, and triangles within a body may bring to mind scales. A spread wing is clearer, and offers a unique silhouette that someone can easily see from afar.