From Exterminatus Manual
The biovore has an artillery like role, deploying spore mines over great distances to deny access to areas or paths to the enemy. Spore mines are large, slow moving, inaccurate projectiles that cause a moderate amount of damage over a large area when detonated. The biovore's slow speed and poor melee attack are are it's major weaknesses.
The biovore's primary attack is his spore mine launcher, which fires in a ballistic arc, allowing him to hit targets beyond his line of sight (behind walls etc.). In it's primary fire mode the spore mines detonate on impact with any player or surface.
Biovores can also deploy spore mines using the Reload key, in this mode the mines will wait until they are damaged or an enemy comes within range before detonating. Each biovore can deploy up to 10 mines at a time this way.
The biovore's secondary attack is his talons, which he normally uses to dig into the ground to stabilize himself for firing. This attack is slow, very short range and not particularly powerful.
Lay traps by deploying up to 9 mines with the Reload key then keep well back. If you die ALL your mines will explode! If you deploy more than 10 mines the oldest mines will detonate. Like other tyranid weapons the spore mine launcher regenerates it's ammunition indefinitely, so you can still use your primary attack to harass the enemy firing one mine at a time and keep 9 other mines deployed as traps.
Spore mines can be detonated by either team shooting at them. Unlike Deathspitter acid, spore mine explosions injure members of both teams, including other mines. This makes using mines at close range and in deployed in clusters a gamble and leaves the biovore vulnerable at medium and short range.