Carpenter ant

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

Team Tactics. The carpenter ant gets +1 damage on every attack for the number of allies that have damaged the creature it is attacking since its last turn.

Spider Climb. The carpenter ant can climb difficult surfaces, upside down on ceilings, without needing to make an ability check.

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 1 piercing damage.

Burrow. Melee Weapon Attack: +10 to hit, reach touch, one target. Hit: 3 piercing damage. The ant can burrow into any creature that is made of wood. Once the carpenter ant uses this action, they are inside of the creature and cannot be removed unless they are killed. They can still be attacked by any way aslong as the attack penetrates to where they are inside the creature ( say acid could be poured into the entrance hole or a perfect cut could hit one). They will eventually exit on their own after four more uses of burrow. Whilst inside a creature, they can still bite, but are more likley to continue to burrow.