Giant Ant (Queen)

Keen Smell. The giant ant has advantage on Wisdom (Perception) checks that rely on smell.

Attack Frenzy. A threatened or injured giant ant can emit an alarm pheromone that attracts allies (ants) from up to 300 feet away and sends nearby ants within 30 feet into an attack frenzy for 1 minute. Frenzied ants have advantage on Strength saving throws, resistance to bludgeoning, piercing, and slashing damage, and gain a +2 bonus to piercing damage rolls. Once the attack frenzy ends, a giant ant must finish a short rest before it can use this feature again.

Pack Tactics. The giant ant has advantage on an attack roll against a target if at least one of the creature's allies is within 5 feet of the creature and the ally isn't incapacitated. 

Multiattack. The giant ant (queen) can make two attacks: one with its bite and one with its sting.

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) piercing damage. Target is grappled (escape DC 13). Until this grapple ends, the target is restrained, and the giant ant can't bite another target.

Sting. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) piercing damage, plus 7 (2d6) poison damage. Target must succeed on a DC 13 Constitution saving throw or be poisoned (variant giant ant: paralyzed) for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.