The ants themselves are probably not chewing on your plants. They may,
however, be "herding" more harmful critters such as aphids, mealies or
scale. Also, they tend to be an indication that your potting medium is
breaking down.

If the ants are the only problem, they're easy enough to get rid of --
submerge each affected pot in a bucket of water. This drives the ants up
onto the foliage where you can get at them. Spray copiously with 50/50
rubbing alcohol and water, this will kill the ants. It will also kill most
of what they might be herding, except that the latter tend to hide in hard
to reach cracks and crevices and may require stronger treatments.
--
Kenni Judd
Juno Beach Orchids
http://www.jborchids.com

"Dada" wrote in message
...
Hi all;

Does black ants cause any damage to the orchids? Common sense tells me
they
might be damaging the roots. I observed a few pots of mine having a
thriving
colony of black ants.!!

What do I use to control the ants.. Some kinda granular pesticide? How
about
neem based pesticides.. will it control them ants?

Dada