It does however make a healer's heart skip and often automatically throw a heal at the lock because it looks like they suddenly took a big hit of damage. Stupid locks LTing in combat.

Lifetap does produce threat, however small. You gain mana from the lifetap - that mana gain produces threat.

"Lifetap does produce threat, however small. You gain mana from the lifetap - that mana gain produces threat."

Not only threat, but threat on everything--same as healing does.

For those who doubt what Healer said: try it. Have one player enter aggro range and run back and the second lifetap (if not full mana), evocate or whatever. The mob(s) will come straight to #2.

Mana, health, I think even energy & rage regens generate small AoE threat. My mage once pulled aggro from a bad tank in heroic SH by bandaging to prove the point.

Great article again from the best writer on the site about the mechanics and play of the game.

No, it doesn't generate any threat, even from the mana gained. Try it out for yourself with a buddy. Have him or her body pull something then life tap next to that mob.