# Exploring the Possibilities: Could an Ant Walk on a Soap Bubble?

• maze
In summary, an ant could potentially walk on a soap bubble due to the low interfacial energy of soapy water compared to pure water and the ant's low foot pressure. However, based on an observer's experiment, the ant may become stuck in the top layer of foam and potentially die.
maze
Could a tiny sugar ant walk on a soap bubble? Would the bubble burst? Would the ant be able to locomote along the surface or would it get stuck?

you can touch bubbles without them bursting, so I guess an ant could.
Find an ant, make a bubble, put the ant on it. It might even work :D

I'm guessing it would be pretty difficult, but an ant could walk across a soap bubble. As mike mentioned, you can make significant sustained contact with a bubble without it bursting. To the ant it may be more like swimming though.

I'm fairly certain that the pull of gravity would move the ant downward, and the traction it could achieve would not be sufficient to counter that pull. It would be like trying to swim up a waterfall.

As Lurch observes, it wouldn't get much traction if it could walk. It would be more like swimming. Whether the ant will be suspened on the surface, be drawn-in, or pop the film depends upon the chemistry of it's legs and what it's been walking in.

One of http://www.bio.miami.edu/~cmallery/150/chemistry/c3x3waterbug.jpg" should manage to sit on a soap membrane.

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People are not considering the fact that soap bubbles have *two* interfaces; the soapy water is a thin film.

Given that the interfacial energy of pure water in air is about 70 dyn/cm (70 erg/cm^2), say the interfacial energy of soapy water about 10 dyn/cm.

An ant weighs about 3 mg, so each 'foot' has 0.5 mg spread over (say) 0.1 mm^2. 'g' ~ 1000 cm/s^2, so each foot exerts about 0.5 dyn/mm^2 (5*10^-3 dyn/cm^2) pressure.

The pressure jump across one interface of a 5 cm diameter soap bubble is 2* 10 dyn/cm * (2/2.5 cm) = 16*dyn/cm^2. This is much higher than the foot pressure of an ant, so the ant's weight should be supported by the bubble.

Usually I have to keep things super clean or else ants will take over, but now that I'm actually looking for sugar ants to drop on a soap bubble, I can't find any.

:/

maze said:
Usually I have to keep things super clean or else ants will take over, but now that I'm actually looking for sugar ants to drop on a soap bubble, I can't find any.

:/

Check outside near the cracks of sidewalks or near the crevices of a patio

Put a piece of food on the ground and wait 30 minutes

Andy Resnick said:
People are not considering the fact that soap bubbles have *two* interfaces; the soapy water is a thin film.

Given that the interfacial energy of pure water in air is about 70 dyn/cm (70 erg/cm^2), say the interfacial energy of soapy water about 10 dyn/cm.

An ant weighs about 3 mg, so each 'foot' has 0.5 mg spread over (say) 0.1 mm^2. 'g' ~ 1000 cm/s^2, so each foot exerts about 0.5 dyn/mm^2 (5*10^-3 dyn/cm^2) pressure.

The pressure jump across one interface of a 5 cm diameter soap bubble is 2* 10 dyn/cm * (2/2.5 cm) = 16*dyn/cm^2. This is much higher than the foot pressure of an ant, so the ant's weight should be supported by the bubble.

Thanks, you taught me ants have 6 legs. I never reely noticed

Ok, I found an ant and dropped it on a soap foam. The bubbles were about 1/2 the size of the ant (ie: 2 bubbles = 1 ant).

The ant basically got stuck in the top layer of foam, immobilized. I believe its body geometry was serving as boundary conditions for the foam surface. After about a second of just sitting there, it spazzed out kicking its legs every way, which caused it to sink slightly to the 2nd or 3rd layer, and then after a couple seconds it stopped moving so I took it out. I think it died, which I didn't expect to happen (especially not after only a few seconds). I don't think I will be trying again since it seems a pretty cruel way to go.

maze said:
Ok, I found an ant and dropped it on a soap foam. The bubbles were about 1/2 the size of the ant (ie: 2 bubbles = 1 ant).

The ant basically got stuck in the top layer of foam, immobilized. I believe its body geometry was serving as boundary conditions for the foam surface. After about a second of just sitting there, it spazzed out kicking its legs every way, which caused it to sink slightly to the 2nd or 3rd layer, and then after a couple seconds it stopped moving so I took it out. I think it died, which I didn't expect to happen (especially not after only a few seconds). I don't think I will be trying again since it seems a pretty cruel way to go.

Thanks for the update as this certainly is interesting.

## 1. Can an ant physically walk on a soap bubble?

Yes, it is possible for an ant to walk on a soap bubble. However, it is not a common occurrence and requires a specific set of conditions to be met.

## 2. What are the conditions necessary for an ant to walk on a soap bubble?

The ant must be small and lightweight enough to not break the surface tension of the soap bubble. The bubble itself must also be strong enough to support the weight of the ant. Additionally, the humidity and temperature of the air can affect the stability of the bubble.

## 3. How does the surface tension of a soap bubble allow an ant to walk on it?

Surface tension is the force that acts on the surface of a liquid and allows it to resist external forces. In the case of a soap bubble, the surface tension is strong enough to support the weight of the ant without breaking.

## 4. Are there any benefits for an ant to walk on a soap bubble?

There are no known benefits for an ant to walk on a soap bubble. It is likely an accidental occurrence and not a deliberate behavior.

## 5. Can other insects or animals walk on a soap bubble?

Yes, other small and lightweight insects or animals may also be able to walk on a soap bubble under the right conditions. Some examples include spiders, water striders, and certain types of beetles.

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