I have been baiting a implement shed for rodents for about a year and a half. I am using rodenticide and LP bait stations ( a LP is a tamper resistant plastic bait holder about one foot square). Norway rats eventually started digging burrows, one active burrow is directly under a baited LP. Over a period of several months I switched bait from Contract to Final to First strike, eventually I got fired from the job!
I am going to offer to do the rat control at this location for nothing,just to even the score a little.
If rats were going to eat poison they should have done it by now. I have a absolute passion for tracking powder but I suspect the dampness from the earth floor and the powder will not get along.This job is about 25 miles away from the office and I cannot afford to drive back and forth very often to baby sit.
I have pretty much gone through the old stand by rodent baits.
I need a new game plan.

thanks much Bob

Sounds like you tried everything but trapping them and other mechanical methods.

This podcast is more oriented around the rodent exclusion but I hope you find it helpful. http://rodentremoval.us/podcast/

I kind of like what LT wrote about rats being nibblers. They will just eat a small amount of your Contrac Blox to see if their body likes it. Sounds like they've got the right idea. I guess I would trail some nice edible food ( your choice ) into cages that are wired open. Once you've got everyone eating regularly, unwire the cages. Preferably about squirrel size.

I know other guys will probably talk about snap traps in the tunnels. Not a bad idea. I also think that if you had non-poisonous bait in the Protectas along with some snap traps to start out with, we may not be having this discussion. Rats can make a worthy adversary. Do Norway rats squeak with a French accent in Canada?

Rodenticides are never a good stand alone solution for an established resident rat population in most cases. An aggressive trapping program is best initiated first with several devices of presentation to keep things looking different. Then after a solid removal program you can then go in and clean out the remaining rats with versatile baiting of some kind.

I am sure there is some kind of food source local to the implement shed or the rats wouldnt be there. Find that source and the routes to and from and set them all heavy and secure them.

Making larger,secure feed boxes from plywood top and bottom with rat size door openings and secureing an edible bait in the center interior of the bait boxes to feed/reward them for a week. Then go back and rebait with the same edible bait, add the ZP/tracking powder on this trip to the bottom of the bait box in line with the door openings leading back to the edible bait holder.The plywood floor will keep the powder dry and they should feed aggressively the first nite on the new baiting thus giving all visitors a lethal dose of ZP with which to groom that nite.

Move the bait box around as needed to other activity areas once one location appears cleaned out, or make enough boxes to cover the other positions as well.

A good norway rat population needs a few implemented methods to really make an effective impact or it will continue to flourish.

one method that I was taught years ago with baits is to cause a competition in the population. one way to do this was to bait a area with grain then to make the bait hard to get to in the station. add the anticoagulants. only put out what would be consumed in the first couple hours of feeding another way is to make the bait only to be eaten in the spot, thus any sub dominates that may have beaten the dom there will try to eat and carry off before the dominate chases them off the food. another thing that would happen in large populous was the residence rats would die off and a new populous would move in and more activity would occur than the original problem. I remember the first time this happened to me I cleaned out the populous fast. things was qt for 3 or 4 days then all heck broke loose. the customer called me in the middle of the night with rats fighting in g the walls. the next morning I called Dr Mike Godfrey I knew him somewhat and he explained the reintroduction that was taking place. but instead of a controlled populous with the dominant rat maintaining control there was a populous of rats trying to take over. it has been 10 years since I have done any major rodent work so things may have changed but it use to be a 1/3 catch with traps and the rest of the clean out with bait, then when the new populous came in the traps again and work the baits. change up was done sometimes on a weekly basis. with a lot of baiting of grain mixed in.

Most poisons have a delayed reaction.A couple days if I remember correctly.As well I have seen rats move out if too many start dieing.There is some liquid poisons that you can add to grain.So you can feed them then poison them.Hard to beet steal.

Jonesie, where do you come up with this stuff? I went on a CC cruise with Dr. Godfrey so long ago that I didn't remember it until you brought him up. You're like the cure for Alzheimer's.

you forgot those days so soon? LOL you know what they say old frats have long term memory but lack short term yesterday stuff LOL CC lol man that is going back some years and I got into some trouble back in those days LOL some of that stuff I want to forget about I still do not know what those blue test tube things had in them. LOL. Dr Godfrey showed me alot about rats. for the life of me I can not remember the name of the guys that showed me alot of the baiting strategies. another thing I use to do for mice was take a 2 in by 2 feet long pvc conduit. half way down the pipe I would put a t with threaded cap. on the ends of the pipe put caps and drill 3/4 inch hole on the edge of the cap so the hole was on the floor when the t with the cap was up. the wax blocks would go into the middle and the mice could go into the pipes and eat. worked good in places where there was shelves along the walls.

Kermit the anticoagulants work in 3 to 5 days, the liquid poison I think are toxicants and work rather fast so it is best to get them feeding on the pre baits fast before you add a toxicant to keep the sublethal dose at a min. again I have not done any rodent work in a while so alot of this may be out dated.

F&Ts sells a smoke bomb that takes up all the air in there tunnels and suffocates them.

Thank you all for the excellent info.
I intend to use non set snap traps, wired open cages,give them some non toxic rat bait,and because there is no water supply I will provide one. After ten days or so comes the big switcharoo plus a little ZP. The rats should be in for a surprise.
I have often read about prebaiting and non set traps. It seems to go against the grain of anything I would want to do to a rat.
Mostly because of your suggestions and expertise (greatly appreciated)I will get off my arse and probably get just about enough right to solve the problem.

thanks much Bob

Bob, I'm not sure if the rest of the guys will agree with me or not. It's been my experience that the longer the rats have been in an area, the more difficult they are to control. Conversely, if a customer calls immediately after the rat or rats have entered, I nail them right away.