A little over a month ago, I took on a house guest.  "Tigger"
owns a friend from a summer job.

There are two issues.  First, my house guest had a few
uninvited guests:  fleas.  I've bought her a flea collar
and am using Hartz Ultraguard (she's due for her second
dose tomorrow), and...it's not completely working.  I
haven't seen any fleas, but she's itching herself.  The
stuff seemed to run out of gas about a week ago.  Still,
there's been progress.  The threadbare cat that I got
from my friend has turned into a stronger, healthier
feline with a soft, silky coat.  In turn, the liking that
Tigger took to me has grown stronger as her health has
improved.

First issue:  anybody got any info to share on Hartz
Ultraguard?  Are there any other remedies that one can
use for this malady (alone or in addition to the ones
I'm using now) that won't cost an arm and a leg--
not that the Babies aren't worth it, mind you, but I've
only got so many arms and legs to go 'round.

I also have to deal with Sweetie.  He got his name for
the way that he is with two-legs.  With smaller mammals,
he has a slightly different personality.  It's sort of a
Jeckyl/Hyde thing.  In many instances, this is a GOOD
thing.  He endeared himself to a former landlord by going
out on the roof of the house and evicting the pigeons
from the gutter.  There was also the small matter of the
mouse that he presented to me for inspection shortly
after my arrival in my current abode.  The only problem
is that he seems to treat other cats the same way.

Which brings up the second issue:  is there anything
that I can do to better integrate this pair?  At the
moment, I've sequestered Tigger in one bedroom, with
occasional open-door intervals.  These invariably end
with Sweetie and Tigger getting into a fight of some-
kind.  Sweetie could weigh twice as much as Tigger,
and he's got a thick, luxurient coat of fur that also
acts as armor when he's fighting.  Though she's good
at squeezing into small areas and using her smaller
size to her advantage, I still fear for her safety.  I
also tried to borrow a screen-of-a-majig from the Singhs.
Didn't do much good.  There's a washer-drier next to the
bedroom door.  I put up the screen, and there was Sweetie--
BOING, PLOP--right there in the thick of things again.
The fun, of course, didn't begin right then.  It waited
until Tigger found a way to slink through the grating.
I should call Liz and let her know I'm going to have
to return it.

Any advice?