Drugs to make rats easier to trap
I keep somewhat up-to-date with pest control measures. I haven't heard of chemicals being used to alter rat behaviour but using parasites that alter rat and mouse behaviour (Toxoplasma spp.) has been studied. The infection increases predation rates and also appears to increase the rate at which they are trapped. Toxoplasmosis also affects humans with cats being the main source of infection. I am uncomfortable about approaches that increase the prevalence of toxoplasmosis.  

If you're going to the trouble of administering a drug to a pest why not make the drug lethal? The extra step seems unnecessary but I personally would opt for traps given that many poisons (particularly warfarin) seem cruel. 

For traps good bait (uncooked bacon, lard, peanut butter, dog biscuits) makes rats; 


  less cautious/sensible and/or more hungry.  


The right trap can make a big difference. This one can self-reload > 20 times and is instantaneous. The linked website contains advice for setting traps.