Just One Bite EX, 128 count, 0.5 OZ, bait blocks are an ideal product to rid rodents. Formula contains the active ingredient bromethalin. To stop feed action rodents cease feeding after consuming a toxic dose. Rats and house mice usually consume a lethal dose in a single feeding, but may take 2 or more days for them to die. Product comes in a 4lb. pail. For rural and agricultural use only.