experimental technique for measuring temperature of an ant I am taking a course on thermodynamics. I have a question from my text(halliday & resnick,physics-1). They asked me to measure temperature of an ant or an insect or a small body,like a small robot. If I build a thin thermometer then it is probable that surface tension would have greater influence than thermal expansion. Then How can I measure the temperature of an ant?
 A: Put ant in small volume of cold water, maybe 5ml. Measure the final temperature of water using some thermometer and solve for temperature of ant using the thermal equilibrium equations.
$$m_\text{ant}c_\text{ant}T_\text{ant} + m_\text{water}c_\text{water}T_\text{water} = m_\text{(ant+water)}T_\text{final}(c_\text{water}+c_\text{ant})$$
$$T_\text{ant} = \frac{m_\text{(ant+water)}T_\text{final}(c_\text{water}+c_\text{ant}) - m_\text{water}c_\text{water}T_\text{water}}{m_\text{ant}c_\text{ant}}$$
Note that you need to measure the mass of the ant and water separately before the experiment. Also, choose a volume of water big enough so that you can use your thermometer. To increase precision, choose a temperature of water that is 'more different' than the temperature of the ant, for example choose water that is much cooler than the ant. Also, conduct the experiment in a short time frame to minimize thermal equilibrium with environment.
A: Alternatively I would look around the lab for an infrared thermometer. There exist in the market close focus ones that go down to 6mm in close focus option ( so as not to advertise, google space accurate infrared thermometers microscopes where I found the number in a one of the first hits). 
I would choose a large ant, or  attract more by a spot of honey and measure their average temperature.
Edit I think finally the answer is like the egg of Colombus,or the Gordian knot) as we say in Greece. Think, do ants have temperature regulator mechanisms?
The egg of Colombus parable : Colombus was sitting at a table and a bowl of boiled eggs came in. All the men around the table played a game of trying to balance the eggs on their narrow end. Colombus said: "what nonsence". and he sat the egg down on its end, breaking it and solving the geometry. :)
A: Ants are cold blooded.  Therefore the temperature of an ant is the ambient temperature in which it exists at the moment.  If the ant is in an environment of variable temperature and is moving around, then it has no temperature in the thermodynamic sense.  If it is in a region of uniform temperature, then that is its temperature.
A: I am not sure, but maybe you can use a micro-thermocouple (https://www.variohm.com/images/datasheets/Micro-Thermocouples.pdf) For example, 44 AWG wire is 0.05 mm diameter, if I am not mistaken.
