Can a summoner's serpentine eidolon with bite and 2 tails with tail slap(3 natural attacks) attack with both bite and 1 tail slam after it has grappled an opponent? The grappling rule states:
Damage: You can inflict damage to your target equal to your unarmed strike, a natural attack, or an attack made with armor spikes or a light or one handed weapon.
I'm stuck on "A natural attack". Does that mean you can only use a single natural attack while grappling? It seems like one of the eidolon's tails would be used for the grapple, but the other tail could still tail slam as a secondary attack and bite as a primary attack.