[chihuahua]

It sounds like it could be Xylocopa violacea, the violet carpenter bee, found in Europe and Asia: https://en.wikipedia.org/wiki/Xylocopa_violacea

[kragen]

I'm in South America, and it doesn't look very similar: http://canonical.org/~kragen/bumblebee.jpeg

I think these are also much larger than the violet carpenter bee.