Gel Baits: Gel baits are very effective roach killers for apartments. They contain attractants that lure cockroaches out of their hiding places. Once ingested, the poison works slowly, which allows the roaches to return to their nests and spread the poison to others. Popular brands include Advion Cockroach Gel Bait and Combat Max Roach Killing Gel.How to Use:Apply small drops of the gel in areas where you’ve seen roach activity, behind appliances, under sinks, and in cracks and crevices.Reapply as needed, following the product instructions. 2. Bait Stations: Bait stations are convenient and less messy than gels. They contain bait that attracts roaches and poison that kills them. Bait stations are placed in strategic locations where roaches are likely to travel.How to Use:Place the bait stations near entry points, along baseboards, and in areas where you’ve seen roaches.Replace the stations every three months or as recommended by the manufacturer. 3. Boric Acid: Boric acid is a natural and effective roach killer. When cockroaches walk through boric acid, it sticks to their legs and antennae. When they groom themselves, they ingest the poison, which kills them.How to Use:Lightly dust boric acid in areas where roaches are active, such as under appliances, along baseboards, and in cracks and crevices.Be careful not to overapply, as a thick layer can deter roaches from walking through it. In case of severe infestations, contact an expert roach control service for complete cockroach treatment.