insted of "warm" marbles, condensor + resitor + led ... discharge condesor simulate evaportation? dont konw about size .. but will be more easy to detect light than heat .... andres ----- Original Message ----- From: "Padu" To: "piclist" Sent: Thursday, September 23, 2004 2:46 PM Subject: [OT]: Suggestions for sensors 3) Ants carry lots of heated marbles (will have to think on how to keep them heated) and they drop one at the time. Other ants follow those marbles by some kind of infra red detection. I saw some cheap robots that are attracted by heat, maybe this is the cheapest solution. _______________________________________________ http://www.piclist.com View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist