I haven't heard or seen anything like this and I'm not sure if it was the seed that was the source for moths or even their eggs. Noticed the other day when visiting my mom that there were several of these small grayish moths flying around, mostly hanging out on the ceiling. She said she got some seed for the Cockatiels and it was only after a few days she noticed the moths. They're tough little buggers to get rid of as she spends once or twice a day in catching them with a vacuum cleaner but there seems to be one or two the escape to start the process again.
Has anyone heard about this or know what might be the cause as I'm thinking it was the cheaper seed she might have picked up from the store.
Bugs, and larvae, in seeds and beddings are not uncommon. I don't know if you could be certain that is where they came from, but I would avoid that brand of seed, and see what happens. If there are a bunch of moths in the processing plant, they could very well lay eggs in the seeds, depending on the species.
Check the seeds for worms.
Some moth species lay their eggs in seeds. Have you heard of rice worm? Very common at wherever there is rice. They feed on rice, and they turn into moths after a while. If there was no worm when you got the seeds, the chance was the seeds had come with moth eggs. Since the eggs are small, you couldn't see them. Maybe you should keep the seeds in the fridge. Worms don't like cold temperature, even if it doesn't kill them it will make them "sleep".
Will let her know that. She purchased a cheaper brand when she was out at the store so that may have been a potential source. I'v known that putting bread in the freezer can extend its life and it could help in keeping the seeds fresher and putting any worms or eggs to sleep.
It claims to be able to prevent moth to lay eggs in your bird seeds.
That actually looks like it could work better than freezing the seed. Let alone if the moths have already hatched and are now just flying around. I'll have to pick up a pair of these for my mom, see how it does.
We have two parrots and shop at a very good, reputable bird specialty store for their food and toys. We complained to the manager once about the larger parrot's more expensive food having moths in it one time. (You're right about it being hard to get rid of those moths once they're flying about!) We were told this just happens sometimes and the moths aren't harmful in the least, but that we could put the bags of parrot food in the freezer as soon as we got home with them. When frozen, it would kill off any unwanted pests. Since we've been doing this, we have never had any moth problem again.