A Ferroseed's home is a nest of spikes, which one must painfully step over or through to approach; should any succeed, they will find a pokemon equally painful to the touch. These creatures have no natural predators, for although fire can damage them badly for a distance, only the extremely rare, horribly lost Talonflame can easily follow it up by actually reaching this pokemon's burnt shell without bleeding horribly from the legs.
Humans, however, have begun to brave this challenge for a different reason; not only do the defenses which protect them from predators (and humans) make them extremely useful in battle, but the iron barbs they use to defend their nests regrow and can be sold for scrap – a valuable source of income for any penniless trainer. Prospective trainers wear heavy boots to get close enough to throw their poke ball, and typically rely on a series of loyal pokemon using primarily ranged attack to weaken them enough for capture. A few follow this up with a flying pokemon such as Pelipper, who can carry the ball back in their bill, but for most trainers the trek to pick up their poke ball is the most painful experience as a pokemon trainer and followed up by a trip to the doctor.
The Ferroseed, for its part, sees its poke ball opened immediately after, in most cases, so that they can remove their spikes – and their new trainers will treasure these pokemon, so as not to let their ordeal go to waste. For a hapless few, however, the trainer turns back from the journey from pain, or collapses onto the spikes and dies – and the Ferroseed remains locked in an unclaimed poke ball until another trainer finally finds them, already captured, and finally begins that pokemon's journey.