Using a Spell-Like Ability
As noted earlier, using a spell-like ability requires a standard action and concentration. It requires nothing else. (Also as noted earlier, a spell-like ability has no verbal, somatic, material, focus, or XP components.)
So what does a spell-like ability look like when it's used? Well, the answer is pretty much any way the user wants it to look and can pull off. When a creature simply uses a spell-like ability without any dramatic flourishes, it still shows some sign that it's concentrating. For example, it might stop moving for a moment, or it may furrow its brow (if it has any brows to furrow) or make some incidental gesture. Note, however, that using a spell-like ability is a purely mental action, and a creature could use one even when bound and gagged or when paralyzed.
再次, 用SP是有征兆的.