New to city. 3 questions
1. Moved to Hampden from large rural area. Know nothing of rats but city fears. Will a few container plantings attract them? Are there "city tips" to repel or discourage them? 2. Photo of a vetch-like mat growing through decorative fence border. What is it? Will it naturally die back or is it invasive and choking preferred plants? 3. Front of house crazy vent pipe (north east exposure). I'll try to finagle a vent re-direct, but what should I do with winter kill? Photo attached
You should be fine with a few container plantings.
Rats will be more attracted to garbage. Here is our page about them: http://www.extension.umd.edu/hgic/rats
Likewise, Baltimore City Department of Public Works has a rat control program. They remind citizens to "eliminate food sources for the rodents by using durable trash cans with tight-fitting lids, picking up dog waste and mowing tall grass and weeds." (http://www.baltimoresun.com/news/maryland/baltimore-city/bs-md-ci-rat-abatement-20141118-story.html)
The city does have a rat eradication program, http://publicworks.baltimorecity.gov/Bureaus/SolidWaste/RatEradication.aspx ( at the time of this writing, this link was not working)
Your mat of green in your photo is Common Chickweed. It is a winter annual, but under the right conditions it can become perennialized. Normally it dies back in the heat of summer, If you don't like it, it is easily pulled.
As far as the dead areas of the plant near your vent, simply trim off the damaged and dead areas of the shrub, and new leaves should flush out this growing season.