Both pigeon nets and anti-pigeon spikes are humane, non-harmful ways to stop birds from nesting on your balcony or ledges — the right choice usually comes down to the shape of the space you're protecting.
Nets work best for fully open areas like balconies, where you need a complete barrier across the whole opening. Spikes are better suited to narrow ledges, window sills, and parapet edges, where a bird would otherwise perch or land, since they only need to cover a thin strip rather than an entire opening.
Many homes actually use both: a net across the main balcony opening, and spikes along adjoining ledges or AC unit tops that a net wouldn't cover efficiently. A quick site visit is usually enough to tell you which combination makes sense for your space.
