Several decades of research on laminar separation bubbles (LSBs) have amassed evidence of an scenario dominated by the convective amplification of incoming disturbances by the inflectional instability. However, some LSBs present dynamics suggesting that additional, self-excited instability mechanisms are also present. This paper reviews some theoretical/numerical results on self-excited instability, and revisits recent low-Tu wind tunnel experiments which provide evidence of the global instabilities. It is concluded that self-excited mechanisms might have been present and overlooked in many previous studies; some considerations are suggested for future research to allow for their identification.