There are a number of devices capable of analysing Infra Red communications.
The most simple are an Oscilloscope with a phototransistor - and a little circuitry, right up to complex protocol analysers, which can analyse the timing, the baud rate - and shift in the data to registers.
If you want some makeshift detection just to see if it is working, a CCD based camera, like a webcam will be able to detect it, it will show as bright white or red flashes from its origin.
Time to build your own robot! Using a Raspberry Pi with parts and some time, you can use my book to learn how to make and program a robot with automatic behaviours.