Seems like this would be difficult. I suppose if a cell released a sudden massive amount of chemical trail, and then was able to taper it off, it could give the illusion that the white cell overshot its target and it should stop or reverse to find it. I imagine the immune system itself has evolved to target a chemical release trail that is more passively released though, and not something the bacterial cell could easily develop an ability to control. Many chemicals released are dissolved gases for example, and may readily diffuse through cell walls without much ability to be concentrated/controlled.

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