Mice are fussy eaters, so tend not to eat most types of poison. Seed-based  poisons seem to work best against mice, but even then there are some populations of mice that are resistant to the some types of poison. There are five types of anti-coagulant poisons available in the UK. Two of which are multi-feed poisons (where mice feed multiple times before they die), and three are single-feed poisons. The trouble is, there are populations of mice who are resistant to the two multi-feed poisons, and resistance is a growing problem in the UK as a whole. Many of the bait products available out there use these multi-feed poisons, but the average person wouldn’t be able to tell the difference.
Single-feed poisons work effectively when they get eaten, but the problem is mice don’t seem to like them so much! So getting rid of mice isn’t as simple as it may seem. Over the years we’ve seen many people, and even some pest controllers from other companies use inappropriate poison products, unsurprisingly without success.