http://breezewiki.vernccvbvyi5qhfzyqengccj7lkove6bjot2xhh5kajhwvidqafczrad.onion/minecraft/wiki/Experience
Unlike resources, experience points are picked up gradually: no matter how many orbs are in the range of the player, they are added to the player's experience one at a time (10 orbs/second). In extreme cases, this can result in the player being followed by a swarm of orbs for many seconds.