PT103 · S1 · Q12 On their way from their nest to

We have reason to think that "ants of most species" would avoid foraging during the afternoon "if it's hotter than 45 degrees Celsius". But we can't say over 50% of all ants only forage in morning / evening. It could be that most ants live in places that don't get as hot as 45 degrees Celsius, and so they're perfectly fine foraging in the afternoon.

We have no way to be quantitatively precise about what is true of "at least 51%" of ants that don't use pheromones. The paragraph only allowed us to say one true thing about "at least 51% of ant species" --- they leave a trail of pheromones. This answer takes what we know, "ants who use the pheromone trail to find their way home would be screwed if they foraged during the afternoon on certain days that got above 45 degrees / the Sahara Desert is one example of a place that can get that hot", and then creates some tortured and specific spin-off of that .... Since the pheromone-ants would be screwed during hot afternoons in the Sahara, "most of the non-pheromone ants choose to live in the Sahara"? We don't know if ANY ants live in the Sahara, from this paragraph.

There's no way for us to support the existence of some mystery substance that can withstand extreme heat. If an ant doesn't use pheromones, maybe it detects electric fields. Maybe it uses food crumbs. Maybe it uses echo-location. There could be myriad ways for it to find its way back home. And even if it does leave a trail of some other substance, that substance can evaporate above 45 degrees. Remember, no one said that any ants live in any places of the world where it gets above 45 degrees, so we don't have to assume that any ants are even facing that constraint in their environments.

This answer is a little frustrating, because it makes a difference what we think is meant by "foraging". If "to forage" simply means "to locate food", then this answer is unsupported, since evaporating pheromones wouldn't hurt an ant's ability to find food; it only hurts the ant's ability to find its way back to the test. If "to forage" means "to locate food and bring it back home", then this answer does seem supportable, because it's reasonable to think that ants will take longer to find their nest (if they do at all) in conditions where their pheromone trail has evaporated. "Forage" just means "to search for food", so there's no reason to think the ants take longer to find the food when their smell-trail back to their nest is evaporating in the afternoon heat. There may even be conditions during the afternoon (better lighting, etc.) that make finding the food easier.