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SEM image of the week: Ants in my plants

Posted on Monday, March 19, 2012 by for SEM.

Spring has sprung in Flatbush, which means insects of all sorts are emerging from the ground looking for things to eat and places to live. Two weeks ago, a group of ants managed to squeeze their way into the Research Room. They seemed especially fond of the water in the saucers under our potted plants. I managed to capture one of these intruders using a piece of double-sided graphite tape.

Good conductivity means low static charge build up. The software running the SEM directs a scanning electron beam to specified positions on the sample at specified times and reads the intensity of the scattered electrons. Static charges deflect the scanning beam (since like charges repel). When the scanning beam is pointed at the wrong place at the wrong time, the resulting image is distorted.

Today’s subject made good, full body contact with the graphite tape. Its small size meant every part of it was close to something conducting. Charge had a hard time collecting on our small friend here, which resulted in nearly distortion free images even at high magnification. Small is better.

Overview of the whole ant showing the main features of insects: three main body segments (head, thorax, abdomen), six legs, two antennae, and two compound eyes. Close up of the thorax, which looks like it could use some grooming.
Close up of the right antenna draped over the right compound eye. The jointed insertion of the right antenna into the head.
The tip of the right antenna. The irregular disk on the second segment from the end is probably a pollen grain. The left antenna draped over the left front leg. The horizontal line in the middle of the image marks the edge of the graphite conducting tape used to fix the specimen in place and ensure good conductivity.

Image credit: Glenn Elert