The most effective, the easiest to use and the safest rat poison is NEOGEN RODENTICIDE 40-Pack Havoc Mouse and Rat Killer. The active ingredient is brodifacoum, which is a highly effective anticoagulant. In case of accidental poisoning, it responds well to the antidote Vitamin K. This poison is contained within a sealed package, and it is visibly marked as a poison. Rats gnaw through the package to get at the pellets. This method of distribution makes it safe to use, but it still must be concealed from children and pets for maximum safety. Rats will perish after one feeding.
Neogen Rodenticide Havoc Chunks Bucket Rat and Mouse Killer
Using the exact same formula as the Havoc 40-Pack Rat and Mouse killer listed above, the Neogen Rodenticide Havoc Chunks Bucket Rat and Mouse Killer is just as effective in an easy to use chunk block. The blocks are exposed so they must be completely hidden for safety, but rat runs behind cabinets or when dropped into holes are the perfect way to distribute these chunks. They are potent after one feeding, and Vitamin K is a highly effective antidote if ingested.
Tomcat Rat Killer ll
If you want safety overall, Tomcat Rat Killer ll with included locking bait station is a solid choice. Made of bromethalin, a substance that is toxic to the nervous system, once consumed, the rats central nervous system shuts down. There is no pain, and the rodent goes to sleep and never wakes up. To comply with EPA regulations, because there is no antidote for this substance, it must be used with a locked bait station so that kids or pets can't get at it. It is effective after one feeding, and the bait station can be unlocked and refilled once the bait is consumed.
Effective and easy to use, Just One Bite II Bait Chunks can be placed anywhere that rats are active, and it will eliminate rats after just one feeding. This anticoagulant formula is made with bromadiolone, which is called "super warfarin." Warfarin was one of the first anticoagulants available on the market, and bromadiolone will kill rats that have built up a resistance to anticoagulants. Vitamin K is the antidote, and care must be used when concealing these chunks to keep them away from children and pets.
For a name you know and trust, go with D-Con Rat & Mouse Bait Pellets. Made with brodifacoum, the same anticoagulant in the best rat killer, these pellets come in easy to use trays. Although there is no difference in killing power over the best rat poison, the D-Con name means you'll pay a premium for this product and the trays may be more difficult to conceal than any of the others on this list. Regardless, one feeding should do the trick and Vitamin K is the antidote.