Red ant eggs are a popular food in North Thailand and Laos and something that I really like to eat when available.

They're seasonal, so living there for a while is the best way to find them. 
When I visit, it's normally 'the wrong time'. Actually, when I lived there is was also the wrong time.
We were lucky enough to have them brought to us twice by Mum and Dad while living down in the South.
I've seen red ants all over Thailand, and presumably they all lay eggs, but the far North and Laos tend to be where you'll find them in popular use as food.

In the North they're sold in the markets when available.
You can eat them there, fully prepared in dishes or you can take them home and cook yourself.
I have no doubt that with sufficient courage, will and possibly stupidity, you could forage your own.
There is a downside to this.
Red ants get understandably upset when you violate the sanctity of their home and  steal their unborn children to slaughter and consume.
They take great exception to it, and tend to swarm all over you in a biting frenzy.

Whilst they aren't exactly piranhas or rottweilers, they do sting a fair bit and it won't go unnoticed.

This particular dish is from Mum-in-law who tends to make either ant egg soup "Gaeng kai mot daeng" or ant egg salad "Yum kai mot daeng"
Both are equally good.

Ant eggs don't taste very 'insecty'
They resemble the soft fluffy ends of cotton buds, mini barley grains, or soft 'rice bubbles' and have a delicate taste, soft appealing texture and a slightly tart edge.

The flavour is lovely and far from being a novelty, the dish is something that could easily become a regular part of the diet or repertoire.

Just a quick explanation on "Gaeng" (or Kaeng, as it tends to get spelt in Thailand when transliterated 'correctly').

We Westerners like quick, easy, logical names and associations.
We like to define, allocate or pigeonhole things neatly.
Thus, I have no idea why our own language is so undisciplined and hard to learn. So many of our words and phrases break the rules that are meant to simplify them.

A "Gaeng" (or "Kaeng") is a curry. In the West we understand what a 'curry' is. usually thickened or creamy – or with a fiery sauce or gravy, not normally clear or watery.
Gaeng Kioew wan – Green curry, for example.
Gaeng is also a stew, a soup or a broth.

Sometimes curry paste is used, sometimes not.
Sometimes liquid is used, and sometimes not. And sometimes that liquid is coconut, and other times water.

This can be confusing when you are trying to learn about Thai food because your thick rich coconut curry is a Gaeng, just like the watery broth with some fish and herbs, or like the stirfry in an oily curry paste.

This "gaeng" is a 'soup', or to put it a little more plainly, ant eggs simmered in broth with some aromats.
There's no 'correct' recipe as every household makes it differently.

A good rule of thumb to start with though, is

• Water
• Red chilli, fresh
• Salt
• Sugar
• Kaffir lime leaf
• Galangal and or lemongrass, sliced and bruised (optional)
• Ant Eggs

The soup normally gets finished off with herbs or greens, and this depends on the season, the garden or the locale in which it's made.

Kaprao leaf is great, and spinach or water spinach is also good for body, colour and texture.

The sky is the limit, and in North Thai gardens and streets there's an abundance of edible leaves and greens which are added to soups. stews and curries – as well as being eaten raw with dips.