A simple technique for delivering liquids directly to the mouth of an unrestrained rat.

The team built a tiny straw that lives inside a rat’s cheek.

A surgeon placed a soft tube under the skin. The end poked into the mouth.

During sessions, the tube dripped sugar water each time the rat pressed a lever. No harness, no human holding the bottle.

The sugar water worked like a charm. Rats pressed again and again.

The tiny straw kept working on every schedule the team tried.

Buskist et al. (1988) later used the same cheek-straw trick. They showed rats will press now for food that arrives much later. The 1968 gadget made that long-term study possible.

Keesey et al. (1968) ran a sister rat lab the same year. They refined fixed-ratio schedules for brain-zap rewards. Both papers sharpened how we measure reinforcement, one with sugar, one with current.

Poling et al. (2011) and Maddox et al. (2015) moved the idea outside. They trained pouched rats to find land mines and people. The lab straw started the line of work that ended up saving lives in the field.

If you run rodent studies, copy the cheek-straw. It gives clean, instant reinforcers without restraint stress. The same setup lets you test delay discounting, drug effects, or shaping new topographies. One small surgery, decades of data.